Dermatology: Practical and Conceptual Review | Dermatol Pract Concept. 2024;14(4):e2024237 1 Clinical and Dermoscopic Characteristics of Cutaneous Chondroid Syringoma: A Systematic Review Antonio Di Guardo1, Charalampos G. Balampanos1, Luca Gargano1, Domenico Giordano1 Alessandro Capalbo1, Flavia Persechino2, Severino Persechino1 1 Department of Dermatology, Sant’Andrea Hospital, Sapienza University of Rome, Rome, Italy 2 Department of Dermatology, Policlinico Umberto I, Sapienza University of Rome, Rome, Italy Key words: Chondroid syringoma, Mixed tumor of the skin, Skin neoplasm, Dermoscopy Citation: Di Guardo A, Balampanos CG, Gargano L, et al. Clinical and Dermoscopic Characteristics of Cutaneous Chondroid Syringoma: A Systematic Review. Dermatol Pract Concept. 2024;14(4):e2024237. DOI: https://doi.org/10.5826/dpc.1404a237 Accepted: July 31, 2024; Published: October 2024 Copyright: ©2024 Di Guardo et al. This is an open-access article distributed under the terms of the Creative Commons Attribution- NonCommercial License (BY-NC-4.0), https://creativecommons.org/licenses/by-nc/4.0/, which permits unrestricted noncommercial use, distribution, and reproduction in any medium, provided the original authors and source are credited. Funding: None. Competing Interests: None. Authorship: All authors have contributed significantly to this publication. Corresponding Author: Antonio Di Guardo, MD, Sant’Andrea Hospital, Sapienza University of Rome, 00185 Rome, Italy. Tel: +39 3341513025. Email: diguardo.antonio96@gmail.com Introduction: Cutaneous chondroid syringoma (CS) is a rare benign mixed skin tumor originating from sweat glands. Despite its rarity, accurate diagnosis and management are crucial due to its poten- tial for malignant transformation. Objective: This study aimed to provide comprehensive insights into the main features of cutaneous CS, encompassing its epidemiology, clinical presentation, and particularly, dermoscopic findings. Methods: A systematic review was conducted to identify relevant literature on CS up to November 2023. Data extraction included clinical and histopathological characteristics from case reports and small case series. Results: The systematic review identified 347 unique CS cases, predominantly benign. Clinical features included a predilection for the head and neck region, with variations in morphology observed. Dermoscopic patterns, although limited, revealed recurrent features aiding diagnosis. Malignant CS cases constituted a notable subset, exhibiting distinct clinical and histopathological features. Conclusion: Cutaneous chondroid syringoma presents with characteristic clinical and histopathological features, necessitating comprehensive diagnostic approaches. Dermoscopy emerges as a valuable tool, although further research is needed to establish definitive patterns. Treatment primarily involves wide local excision, with collaboration among clinicians essential for optimal management. Future studies are warranted to address existing knowledge gaps and enhance understanding of this rare skin neoplasm. ABSTRACT 2 Review | Dermatol Pract Concept. 2024;14(4):e2024237 Introduction Cutaneous chondroid syringoma is a rare benign mixed skin tumor originating from the sweat glands and belongs to the larger category of cutaneous adnexal neoplasms [1]. In 1859, Billroth described what he called a “mixed tumor of the skin,” which was histologically similar to the benign mixed tumors of salivary gland origin [2]. A century later, in 1961, Hirsch and Helwig introduced the term “chondroid syringoma” to describe this tumor, characterized by the presence of sweat gland elements within a cartilage-like stroma. This nomencla- ture reflects the dual origin of the tumor and underscores its unique histopathological features. CS accounts for less than 0.2% of all diagnosed skin tumors [3]. Chondroid syringoma typically manifests on the head and neck area, particularly on the nose, cheek, and upper lip, although cases involving other regions such as the trunk, genital area, and extremities have also been reported. Clinically, it often presents as a sol- itary well- circumscribed asymptomatic painless firm-to-hard slow-growing lobulated nodule, rarely exceeding 2 cm in di- ameter [1, 3]. A consistent feature of chondroid syringoma is the absence of ulceration. The color of the lesion varies from skin-colored to erythematous, with rare cases exhibiting pig- mentation. Malignant transformation is rare but should be suspected in cases of large-sized chondroid syringoma located on the extremities and trunk in young women. The differ- ential diagnosis should include other adnexal tumors and non-melanoma skin cancers such as basal cell carcinoma. His- tologically, chondroid syringoma presents as a well-defined multilobulated tumor mass separated by fibrous septa, situ- ated in the dermis and/or subcutaneous tissue with epithelial and stromal components [4, 5]. The stroma may exhibit a ho- mogeneous bluish chondroid appearance but can also be myx- oid or densely collagenous, eosinophilic, and hyalinized. The epithelial component comprises cuboidal or polygonal cells forming glandular-like structures, nests, or cell strands that give rise to ducts and tubules. Immunohistochemistry may be necessary for diagnosis in rare cases where doubt exists. Objective The aim of this study was to comprehensively define the main epidemiological characteristics, clinical presentations, and course of cutaneous chondroid syringoma, both in its benign and malignant forms. Special attention was given to cases where the dermoscopic pattern was reported. The main limitation of this systematic review is its reliance on case re- ports and small case series. Methods For the case described herein, we collected pertinent data in- cluding sex, age, personal medical history, and dermoscopic features of the cutaneous lesion (Heine DELTA30, 10 × magnification). Additionally, a comprehensive histological description of the specimen was provided. Subsequently, a thorough review of both benign and malignant chondroid syringomas reported in the existing literature was conducted. The data for this review adhered to the Meta‐analysis of Ob- servational Studies in Epidemiology (MOOSE) reporting guidelines and the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines [6, 7], as detailed in Supplementary file - Figure S1. Given the nature of the available literature, which primarily consisted of case reports and small case series, no formal methods were em- ployed to assess the risk of bias in study design or reporting. When necessary, authors of the articles were contacted, and reference sections were meticulously examined to ensure in- clusion of all relevant reports, including unpublished data. Search Strategy A systematic literature search was conducted from incep- tion to November 24th, 2023, encompassing the PubMed, EMBASE, and Cochrane CENTRAL databases. The search terms “chondroid syringom*” and “mixed tumour AND cutaneous” were employed across all databases. A detailed search strategy for PubMed is outlined in Supplementary File. Chondroid syringomas were categorized into two groups based on reported histopathological and clinical fea- tures: benign/atypical and malignant, as delineated in Sup- plementary File. Data Extraction Clinical information retrieved from the case reports and small series encompassed sex, age, ethnicity, past medical history, description of clinical lesions, imaging, histopathol- ogy, treatment modalities, and disease outcomes. All statisti- cal analyses were conducted using R (ver. 4.0.2) and RStudio (ver. 1.2.5033) [8], with descriptive statistics, including fre- quencies and percentages, computed for all variables. Results Systematic Review In this review, a total of 387 relevant articles were initially identified using the specified search criteria. Additionally, 27 supplementary articles were obtained from the reference lists of review publications and subsequently included in this re- view. After the removal of 54 duplicate records, 241 articles remained following the initial screening based on title and ab- stract. Subsequent full-text assessment led to the exclusion of 34 studies due to unavailability, irrelevance to the topic, or being categorized as a review/meta-analysis. Out of the 207 remaining articles, five were further excluded due to reporting collisions between different adnexal tumors (4/5) or collision Review | Dermatol Pract Concept. 2024;14(4):e2024237 3 of chondroid syringoma with other lesions (1/5). Conse- quently, a total of 202 publications were utilized, collectively representing 347 unique patients. It is noteworthy that all the publications included in this review were either single case re- ports or small case series, with no cohort studies or random- ized controlled trials identified. A comprehensive summary of data derived from reported cases of benign and atypical chondroid syringomas in the literature is presented in Table 1, while cases of malignant chondroid syringomas are delineated in Table 2. The list of publications included in this systematic review is presented in Table 3. Among the included 347 cases, 290 were histopathologically categorized as benign (83.6%), 50 as malignant (14.4%), and seven as atypical (2%). Age and maximum diameter variables were categorized into groups, with the number of cases considered for each variable varying based on availability within the studied works. Benign/Atypical CSs Of the 297 listed cases of benign and atypical chondroid sy- ringomas (CS), 179 were male (60.27%) and 118 were fe- male (39.73%), resulting in a male-to-female ratio of 1.5:1. The average age at diagnosis was 52.4 years, with a median age of 54 years and an age range from 0.5 to 88 years. The highest incidence was observed in the age group ranging from 49 to 64 years (71/229 - 31%), followed by the age group from 65 to 78 years (52/229 – 22.7%). The incidence was relatively low in the age group from 0 to 18 years (4/229 - 1.75%). Regarding anatomical site, the majority of CS cases were located on the head and neck (208/287, 72.5%), specifically on the eyelid and periocular area (40/287), nose and perinasal area (34/287), and lips (17/287). Addition- ally, 54 cases (18.8%) were noted on the limbs, with fre- quent locations including the sole and foot (20/287) and the Table 1. Epidemiology, Clinical Morphology, Dermoscopic Features, and Histology of Benign and Atypical Chondroid Syringomas. Cases/ Articles M/F Ages (K-Means) (n = 229) Site (n = 287) Max Diameter (n = 287) Clinical Morphology (n = 164) Dermoscopic Features (n = 5) Histology (n = 297) 297/155 179/118 M: 60.27% F: 39.73% 0-2: 1 (0.4%) 3-5: 0 (0%) 6-13: 1 (0.4%) 14-18: 3 (1.3%) 19-33: 29 (12.7%) 34-48: 60 (26.2%) 49-64: 71 (31%) 65-78: 52 (22.7%) 79 and over: 12 (5.2%) - NP: 68 Media: 52.4 yrs Median: 54 yrs Range: 0.5 – 88 yrs Head and neck: 208 (72.5%) Scalp: 15 Forehead/ glabella: 8 Ear/External ear canal: 12 Eyelid/Periocular: 40 Nose/Perinasal: 34 Cheek: 18 Lip/philtrum: 17 Neck: 4 Chin: 3 Trunk: 23 (8%) Chest/Breast: 7 Abdomen: 1 Axilla: 6 Back: 5 Gluteus: 1 Genitalia: 2 (scrotum), 2 (vulva) Limbs: 54 (18.8%) Arm/elbow: 7 Forearm: Hand/Wrist: 14 Thigh: 4 Leg: 3 Foot/Ankle: 20 Multiple sites: 4 (1.4%) NP: 8 ≤ 0.5 cm: 17 (5.9%) 0.6- 0.9 cm: 34 (11.8%) 1.0-1.9 cm: 67 (23.3%) 2.0– 2.9 cm: 33 (11.5%) 3.0– 3.9 cm: 23 (8%) ≥ 4.0 cm: 27 (9.4%) Median diameter: 1.9 cm Range: 0.3-13 cm NP: 100 Firm superficial nodule/ mass (with or without skin involvement): 82 (50%) Deep subcutaneous lesion (with intact overlying skin): 42 (25.6%) Protruding/pedunculated mass: 40 (24.4%) Additional clinical features (records yet included in previous classification) Periocular mobile lesion: 15 (9.1%) Pseudo-cystic appearance: 9 (5.5%) Telangiectasias: 8 (4.9%) Giant mass (>8 cm): 7 (4.3%) Ulceration and bleeding: 6 (3.7%) Multiple lesions: 4 (2.4%) Keloid-like: 1 (0.6%) NP: 133 White structures/ streaks and “cotton-white” area: 4/5 Telangiectatic vessels: 3/5 Homogenous erythematous background: 3/5 Milia-like cysts: 2/5 “Crown” of vessels: 1/5 Erythematous rim at periphery: 1/5 Curved vessels: 1/5 Homogeneous whitish-blue color pattern: 1/5 Brown blotches: 1/5 “Marble” appearance (mixture of with and red structure) Benign: 290 Atypical: 7 Abbreviations: F: female; M: male; n: records included in every column; NP: not published. 4 Review | Dermatol Pract Concept. 2024;14(4):e2024237 while seven records (4.3%) presented as “giant” masses (≥ 8 cm). Additionally, one case was described with a ke- loid-like clinical appearance. Dermoscopy descriptions were available for only five cases. Most benign CS lesions pre- sented with white structures or the so-called “white-cotton” area (4/5), followed by telangiectatic vessels (3/5). A homo- geneous erythematous background and milia-like cysts were observed in more than one case. Moreover, unique dermo- scopic patterns such as a “marble” appearance, erythema- tous rim at the periphery, and a vascular “signet ring” (as seen in our case) were described. Malignant CSs Out of the 50 listed cases of malignant chondroid syringo- mas (MCS), 28 cases were female (56%), and 22 cases were male (44%). The average age at MCS diagnosis was 52.4 years, with ages ranging from 13 to 93 years. A substan- tial number of these cases were located on the limbs (23/50; hand (14/287). The trunk and genitalia accounted for 8% of cases (23/287), with two cases reported on the scrotum and two cases on the vulva. Multiple sites were observed in four cases of benign CS (1.4%). In terms of maximum diameter, a significant portion of reported cases measured between 1.0 to 1.9 cm in size (67/287; 23.3%), followed by lesions ranging from 0.6 to 0.9 cm (34/287; 11.8%). Notably, 9.4% (27/287) of the studied cases were large in size (≥ 4 cm). The median size of benign/atypical CSs was 1.9 cm, ranging from 0.3 to 13 cm. The most common clin- ical morphology observed was a firm superficial nodule or mass, with or without skin involvement, accounting for 82 records (50%). Other frequently encountered clinical types included a deep subcutaneous lesion with intact overlying skin (42/164; 25.6%) and a protruding or pedunculated mass (40/164; 24.4%). Pseudo-cystic appearance was re- ported in nine cases (5.5%). Superficial macroscopic telangi- ectasias were observed on the surface of eight lesions (4.9%), Table 2. Epidemiology, Clinical Morphology, and Metastatic Behavior of the Malignant Chondroid Syringomas. Cases/ Articles M/F Ages (n = 50) Site (n = 50) Max Diameter (n = 35) Clinical Morphology of Primitive Lesion (n = 47) Metastasis, Local Invasion and Recurrences (at Time of Diagnosis) (n = 47) 50/47 22/28 M: 44% F: 56% 13 14 18 22 24 25 31 32 32 33 33 34 37 40 40 41 44 44 46 48 49 50 51 52 52 53 54 55 57 60 60 61 61 61 63 64 72 72 75 77 78 79 81 81 82 83 84 86 89 93 Media: 52.9 yrs Median: 52 yrs Head and neck: 19 (38%) - Scalp: 6 - Forehead/glabella: 1 - Ear/External ear canal: 1 - Eyelid/ Periocular: 1 - Nose/Perinasal: 3 - Cheek: 4 - Neck: 3 Trunk: 8 (16%) - Chest/Breast: 1 - Abdomen: 2 - Axilla: 1 - Back: 3 - Gluteus: 1 Limbs: 23 (46%) - Arm/elbow: 3 - Forearm: - Hand/Wrist: 5 - Thigh: 3 - Leg/knee: 3 - Foot/Ankle: 9 - Multiple sites (records yet included in previous classification): 2 (4%) - ≤ 0.5 cm: 0 (0%) - 0.6- 0.9 cm: 1 (2%) - 1.0-1.9 cm: 6 (12%) - 2.0– 2.9 cm: 5 (10%) - 3.0– 3.9 cm: 6 (12%) - ≥4.0 cm: 17 (34%) Median diameter: 4.0 cm Range: 0.7-19 cm NP: 15 - Firm superficial nodule/ mass (with or without skin involvement): 15 (31.91 %) - Deep subcutaneous lesion (with intact overlying skin): 19 (40.43 %) - Protruding/pedunculated mass: 8 (19.15 %) - Infiltrative lesion: 5 (10.64 %) Additional clinical features (records yet included in previous classification) - Ulceration: 8 (17.02%) - Periocular mobile lesion: 1 - Pseudo-cystic appearance: 1 (2.13%) - Telangiectasias: 2 (4.26%) - Giant mass (>8 cm): 14 (29.79%) - NP: 3 - Distant metastasis: 9 (19.15%) Lung and pleura: 6/9 Brain: 4/9 Bone: 3/9 Liver: 2/9 Spinal cord: 1/9 Kidney: 1/9 Thyroid: 1/9 - Nodal metastasis: 14 (29.79%) - No metastasis: 27 (57.45%) - Unknown staging: 3 - Local Recurrence: 9 (19.15%) - Local invasion: 5 (10.64%) Abbreviations: F: female; M: male; n: records included in every column; NP: not published. Review | Dermatol Pract Concept. 2024;14(4):e2024237 5 Table 3. List of Publications Included in This Systematic Review. Author Year Age Sex Site Cases Clinical Morphology Dermoscopy Histology Halpert 1933 60 M Bridge of the nose 1 1) the shape of the “end of a sausage”, measured 3 x 2 x 2 cm NP Benign Rabinovitch 1948 36 M Bridge of the nose 1 Irregular raised nodular deformity over the bridge of the nose of a maximum diameter of 1.2 cm NP Benign Mark 1951 37 F External auditory meatus 1 Firm mobile circumscribed nodule NP Benign Lennox 1952 26, 69, 53, 23, Adult F, M, F, NP, M Glabella, Nose, Finger, Foot, Thigh 5 Lump or nodule NP Benign Klein 1956 Adult F Vulva 1 NP NP Benign Greeley 1956 50 M Cheek 1 Firm non-tender freely moveable tumor NP Benign Rosborough 1963 83 F Upper arm 1 Painful, mobile mass 3 cm NP Malignant (with nodal metastasis) Khoo 1964 51 M Middle toe 1 Firm and tender mass with superficial ulceration and sinus discharge (3 x 2 cm) NP Benign Matz 1969 80 F Parieto- occipital region of the scalp 1 Firm elevated irregular oval- shaped skin lesion, 5 x 3.5 x 2.5 cm NP Malignant (with local recurrence and nodal metastasis) Hilton 1973 14 F Arm 1 A recurrent lump with cystic appearance NP Malignant (with local recurrence) Webb 1975 52 F Medial aspect of the right thigh 1 Firm freely mobile swelling measuring 10 x 4 cm with cystic appearance NP Malignant (with local recurrence) Hernandez 1976 39, 40 F, M Scalp, Chest 2 1) Subcutaneous, well- circumscribed gray-white, firm, glistening nodule measuring 0.8 cm in diameter (suspected diagnosis: sebaceous cyst) 2) Well-circumscribed nodule measuring 1 cm in diameter NP Benign Silva 1976 39 F Sole 1 Painful ulcerated nodule simulating a poroma NP Benign Dissanayake 1980 79, 33 F, M Sacrum, Sole 2 1) Well circumscribed mass, 8 x 6 x 5 cm, with intact overlying skin; 2) Plantar nodule NP Malignant (1. pulmonary metastasis, 2. multiple lung metastasis) Gupta 1982 48 M Left thigh and left leg 1 Fungating growth of 15 x 10 cm in size on the anteromedial aspect of left leg with multiple hard grayish nontender nodules on left thigh NP Malignant (with multiple lesions and local recurrence) Table 3 continues 6 Review | Dermatol Pract Concept. 2024;14(4):e2024237 Author Year Age Sex Site Cases Clinical Morphology Dermoscopy Histology Redono 1982 61 F Sole 1 2.5-cm firm, tender nodule with intact overlying skin NP Malignant (with local invasion and nodal metastasis) Manni 1983 29 M Tip of the nose 1 Firm semi-mobile nodular tumor (2 cm in size) NP Benign Ishimura 1983 73 M Back 1 Firm protruding slow- growing tumor measuring approximately 7 X 5 cm in size NP Malignant (with local recurrence, nodal and widespread metastasis) Devine 1984 72 M Sole 1 Slowly enlarging mass NP Malignant (with bone metastasis) Shvili 1986 44 F Gluteal region 1 Tender mass with a maximum diameter of 5 cm NP Malignant (with nodal metastasis and multiple visceral metastasis) Terrill 1987 65, 29 M, F Dorsum of the hand, index finger 2 1) 8 cm, irregular, lobulated, nontender, rubbery firm mass; 2) 1 cm, firm and rubbery, not adherent to flexor tendons or skin NP Benign Scott 1988 61 M Back of the neck 1 Soft ulcerated pedunculated nodule measuring 5 x 4 x 3 cm NP Malignant (nodal metastasis) Sánchez Yus 1988 72 F Nose 1 Firm pedunculated 3 cm mass NP Malignant Steinmetz 1990 59 M Scapula 1 Large scapular subcutaneous mass (4.0 X 2.5 X 1.6 cm) NP Malignant (nodal and distant metastasis) Watson 1991 25 F Dorso- lateral aspect of the foot 1 Tender swelling NP Malignant (local secondary deposit in the foot bone) Stromberg 1991 Adult M Face 1 NP NP Atypical Wenig 1992 13 F Septum of the nose 1 Obstruction and epistaxis NP Malignant (metastasis - 31 yrs.) Martorina 1993 81 M Lower eyelid 1 Painless well-demarcated roughly polypoid lesion approximately 18 x 15 x 15 mm in size NP Benign Gottschalk- Sabag 1994 82 F Axilla 1 Subcutaneous mass NP Benign (cytology) Trown 1994 22, 89 M, M Sole, Neck 2 1) Circumscribed nodular mass of maximum diameter 3.5 cm, with a cystic and hemorrhagic surface 2) Pale slightly raised lesion with a well-defined erythematous edge NP Malignant (with eccrine differentiation) Table 3. List of Publications Included in This Systematic Review. (continued) Review | Dermatol Pract Concept. 2024;14(4):e2024237 7 Author Year Age Sex Site Cases Clinical Morphology Dermoscopy Histology Tang 1994 39 M external auditory canal 1 Freely movable firm polypoid mass NP Benign Zumdick 1995 85 M Upper lip 1 Firm papillomatous nodule NP Benign (with apocrine differentiation) Hong 1995 40 M Suprapubic region 1 Well-circumscribed nodular mass measuring 7.0 x 3.5 x 2.5 cm NP Malignant Torii 1995 52 F Wrist 1 Hemispherically elevated elastic hard subcutaneous nodule NP Benign Nakayama 1996 52 M Neck 1 Firm discrete partially cutaneous and partially subcutaneous nodule (2 cm in size) NP Benign (hyaline cell-rich CS) Kim 1996 45, 35, 53 F Forehead 3 1) Numerous rice-sized skin colored papules; 2) Skin-colored papules; 3) Multiple skin-colored papules NP Benign Chen 1996 60 F Nasofacial groove 1 Asymptomatic mass NP Benign Poku 1996 65 M Scrotum 1 3–3.5. cm firm, subcutaneous mass NP Benign Shimizu 1996 68 F Upper lip 1 Firm mass measuring 3 x 2 x 2 cm NP Benign (with marked ossification) Kakuta 1996 35 M Cheek 1 Skin-covered relatively firm bottom-adhered tumor approximately 6 cm in diameter NP Benign Tyagi 1996 41 M Upper eyelid 1 Firm nodular mass NP Benign Sun 1996 18 M Foot 1 Protruding mass on the sole surface NP Malignant Kiely 1997 50 F Hand 1 Primitive lesion is not described NP Malignant (lung metastasis due CS resected 17 yrs previously) Bisceglia 1997 64 M External ear 1 NP NP Benign (hyaline cell-rich CS) Akasaka 1997 58 M Chin 1 Slightly reddish, 18 x 21 mm, dome-shaped nodule with telangiectasia on the surface NP Benign (ossification, hair matrix, and sebaceous ductal differentiation) Bhargava 1997 29 M Nasal tip 1 Round intradermal nodule NP Benign Nakamura 1998 72 M 2 lesions in maxillary region and ear lobe 1 Both skin tumors were firm, light brown in color, dome-shaped; their sizes were 25 x 30 mm and 30 x 40 mm in diameter NP Benign (multiple and recurrent CS) Table 3. List of Publications Included in This Systematic Review. (continued) Table 3 continues 8 Review | Dermatol Pract Concept. 2024;14(4):e2024237 Author Year Age Sex Site Cases Clinical Morphology Dermoscopy Histology Bates 1998 Adult M, M, F Toe, Foot, Finger 3 Size (longest length in cm): 3, 2, 2 NP Atypical CS Nakayama 1998 55, 36, 45, 42, 39, 55, 60, 52, 70 6 M, 3 F Shoulder (1), Face (6), Neck (2) 9 Diameter (cm): 3.5, 0.7, 1.5, 1.5, 0.7, 1 .0, 0.7, 2.0, 2.0. NP Benign Agrawal 1998 40 F Scalp (occipital region) 1 Recurrent subcutaneous 6 cm x 4 cm, soft swelling adherent to the operative scar NP Malignant (with recurrence) Hardisson 1998 64 M Axilla 1 Painless subcutaneous tumor measuring 8.3 x 7.3 x 6.5 NP Benign Kitazawa 1999 84 F Canthal region 1 Firm well-demarcated, polypoid tumor, approximately 2.5 x 1.5 cm NP Benign Yamamoto 1999 45, 80, 68, 44, 73, 25, 77, 35 2 F, 6 M Upper lip, cheek, nose, ear, eyebrow 8 NP NP Benign Park 2000 55 F Medial aspect of the right proximal leg 1 Well-circumscribed egg-sized mass with a protrusion in the central area but with no ulceration (3 × 3 × 4 cm in size) NP Malignant Sheik 2000 28 F Thigh 1 Well-circumscribed 2.5 cm firm-to-hard nodule with a shiny smooth white cut surface NP Benign Barnett 2000 24 M Foot 1 Recurrent nodules on sole NP Malignant De Fata Chillón 2001 76 M Scrotum 1 Solid scrotal mass (4.2 cm in diameter) NP Benign Hasson 2001 55 F Cheek 1 Multifocal rounded mobile solid tender lesions with intact overlying skin NP Benign Nicolaou 2001 54 M Thenar eminence 1 Firm lobulated 4.5 cm × 3.5 cm lesion. Some dilated veins were visible beneath the surface. NP Malignant (low-grade) Mencía- Gutiérrez 2001 71, 60 M, F Upper eyelid, upper eyelid 2 1) Smooth firm rounded well-circumscribed elevated lesion of polypoid appearance, measuring 1.3 cm in diameter 2) Mass of verrucose aspect, rounded, well-circumscribed, measuring 0.4 cm in diameter NP Benign Medina Henriquez 2001 37 M Hand 1 2 cm hard subcutaneous nodule which was adherent to the skin NP Malignant (nodal metastasis) Rege 2001 45, 40 M, M Neck, Cheek 2 Cutaneous or subcutaneous swellings NP Benign Table 3. List of Publications Included in This Systematic Review. (continued) Review | Dermatol Pract Concept. 2024;14(4):e2024237 9 Author Year Age Sex Site Cases Clinical Morphology Dermoscopy Histology Nemoto 2002 56 F Little finger of the right hand 1 Soft tumor with a diameter about 10 mm NP Benign Reis-Filho 2002 29 M Palmar aspect of hand 1 Slowly enlarging flesh- colored nodule measuring 2 cm in maximum diameter NP Benign (Hyaline cell-rich CS) Miracco 2002 65 M Scalp 1 Painless nodule in the vertex NP Benign (lipomatous mixed tumor) Yavuzer 2003 23-65 10 M, 6 F Face and upper extremity 16 NP NP Benign Satter 2003 25 M Upper lip 1 Slowly enlarging nodule appearing after minor trauma to the area NP Benign Sungur 2003 55 M Shoulder 1 Clinically malignant mass measuring 10 x 8 x 10 cm NP Benign Arikan 2004 72 M Upper lip 1 Firm non-tender nodular mass NP Benign Shashikala 2004 32 F Scalp 1 Mass 5 x 4 cm in size with an irregularly nodular surface and firm-to-hard consistency NP Malignant Gee 2004 40 M Cheek 1 Firm rubbery subcutaneous nodule with a more superficial protuberant lesion arising within it NP Benign Chao 2004 46 M Chin 1 Firm painless mass (1.4 x 1.2 x 1.4 cm) with a smooth surface except for the lower portion, which was ulcerative NP Benign Awasthi 2004 43 M Cheek 1 5 cm in diameter, firm non- tender freely mobile lump NP Benign (with extensive ossification and marrow formation) Takahashi 2004 22 F Left big toe 1 25-mm dome-shaped ulcerated nodule NP Malignant (recurrent and with bone invasion) Mandeville 2004 22, 34, 36, 45, 52, 54, 58, 65, 73 4 F, 5 M Periocular 9 Enlarging/recurrent/inflamed nodule NP Benign Radhi 2004 46 M Scalp 1 Scalp nodular lesions. The tumors were mobile and slowly increasing in size. NP Benign (with small tubular lumina) Kaushik 2005 57 F External auditory meatus 1 Non-tender smooth firm lesion NP Benign Smiri 2005 NP M Face 7 Single painless skin lesion of about 1,5 cm NP Benign Table 3. List of Publications Included in This Systematic Review. (continued) Table 3 continues 10 Review | Dermatol Pract Concept. 2024;14(4):e2024237 Author Year Age Sex Site Cases Clinical Morphology Dermoscopy Histology Mathiasen 2005 64 M Infraorbital facial skin 1 6-mm erythematous papule NP Malignant (with recurrence) Ogawa 2006 61 F Lower eyelid 1 Painless and slowly developing mass (31 x 22 x 19 mm) NP Benign Villalón 2006 67, 77, 58, 60, 71, 44, 46, 63 Lip, Ear, Nose, Mandibula 8 Well-defined bluish nodular lesions with a smooth shiny surface (max diameter: 5-10 mm) Case 4: Well- defined edges and with a homogeneous whitish-blue color pattern Benign Gündüz 2006 46 M Lower eyelid 1 Solid painless mass (20 x 15 x 15 mm in size) NP Benign Karnwal 2006 40 M External ear canal 1 Fluid-containing cyst NP Benign (cystic structure) Kuwabara 2006 69 F External auditory canal 1 Painless mass NP Benign Kerimoglu 2006 53 F Proximal right pretibial region 1 Nodular subcutaneous painless mobile mass. NP Benign Mebazaa 2006 43 F Arm 1 Firm painless mobile 2-cm nodule covered by normal skin. NP Benign Sivamani 2006 84 M Glabella 1 Enlarging bluish painless subcutaneous nodule NP Benign Eccher 2007 27 M Frontal region 1 Slow-growing nodule localized in the subdermis NP Benign (with extensive ossification) Torres González 2007 29, 50 F, M Nostril, dorsum of the nose 2 1) Exophytic pedunculated smooth skin-colored firm lesion, 8 mm in diameter and; 2) Well-circumscribed firm hemispherical nodular lesion (5 mm in diameter) NP Benign Kazikdas 2007 26 F Helix 1 Firm 1 x 1-cm freely mobile superficial mass NP Benign Cýralýk 2007 72 M Axilla 1 Subcutaneous painless, mobile, and slowly increasing in size (3 cm in diameter) NP Benign Choudhury 2007 45 F Multiple sites 1 Multiple masses in the flank, chest wall, arm, -thigh and neck NP Benign Varsori 2007 84 M Lower eyelid 1 Adherent asymptomatic subcutaneous nodule NP Benign Ryu 2007 46 M Heel 1 Painless and mobile nodular mass NP Benign Markou 2008 60 F External ear canal 1 Exophytic mass NP Benign Table 3. List of Publications Included in This Systematic Review. (continued) Review | Dermatol Pract Concept. 2024;14(4):e2024237 11 Author Year Age Sex Site Cases Clinical Morphology Dermoscopy Histology Ogawa 2009 40 M Lower lip 1 Skin tumor that was hard, well-demarcated (keloid-like) NP Benign Hafezi-Bakhtiari 2009 71 F Scalp 1 Slow-growing 2.0 × 2.0 × 1.0 cm nodule scalp NP Benign (with predominant myoepithelial component) Magro 2009 74 F Breast 1 6-cm firm painless freely mobile pedunculated mass, with a smooth polylobulated external surface covered by normal skin, focally ulcerated NP Benign (with lipomatous differentiation) Brewer 2009 20 M Left nostril 1 1-cm firm lobular mass with telangiectasias NP Benign Baran 2009 47 M Eyebrow 1 0.7 cm lesion NP Benign Borman 2009 56 M Hand 1 Soft and fixed subcutaneous mass NP Benign Siddaraju 2009 43 F Dorsum of the nose 1 0.8 × 0.8 cm soft-to-firm, tender, and not fixed to the underlying bone swelling NP Benign Kakitsubata 2009 58 M Arm 1 Large palpable mass in subcutaneous tissue NP Benign Skoro 2010 63 M Neck 1 Small soft nodule NP Benign Tokyol 2010 57 F Philtrum 1 Slow-growing lump NP Benign Beals 2010 42 F Forefoot 1 Non-tender 1.5-cm firm mass on the medial side of the forefoot NP Benign Sirivella 2010 66 F Right chest 1 Firm non-tender slightly bulging mass (measuring 9 cm × 5 cm) covered by skin with a pinkish-purple hue. NP Benign Kumar 2010 20 M Dorsum of nose 1 Firm non-tender swelling NP Benign Dubb 2010 32, 18, 23 F, F, M Scalp, upper lip, scalp 3 1) 2-cm mass involving the skin/soft tissue; 2) 0.5-cm mass; 3) 2-cm mass involving the skin/soft tissue NP Benign Zirbs 2011 81 F Lower eyelid 1 Skin-colored slow-growing tumor NP Benign Sánchez Herreros 2011 93 F Nasal ala 1 Reddish 2.5-cm ulcerated firm nodule NP Malignant Watarai 2011 46 M Sole 1 Solitary dome-shaped skin-colored firm nodule measuring 30 mm x 30 mm, NP Malignant (nodal metastasis) Table 3. List of Publications Included in This Systematic Review. (continued) Table 3 continues 12 Review | Dermatol Pract Concept. 2024;14(4):e2024237 Author Year Age Sex Site Cases Clinical Morphology Dermoscopy Histology Solanki 2011 16, 21 M, F Nose, cheek 2 1) Well-defined non-tender mobile nodule of 1.5 cm x 1.5 cm with slight violaceous discoloration in its center; 2) Well-defined nodule of 4 cm x 3 cm, firm-to-hard in consistency, non-tender. NP Benign Sirinoğlu 2011 63 M Fifth toe 1 Subcutaneous mobile mass with rubber consistency, approximately 3 x 2 x 1 cm in size NP Benign Paik 2011 51 M Scalp (parietal area) 1 Firm painless mobile, 1 × 1-cm nodule covered by skin and located NP Benign Kazakov 2011 32, 29, 44, 66 M, M, M, F Nose, Nose, Forehead, Fifth toe 4 1) Solitary nodule (3 x 2 cm); 2) Solitary 1.5 x 0.8 cm; 3) Solitary 1.5 cm nodule (preoperative diagnosis: trichilemmal cyst) 4) Solitary 1.5 cm nodule NP Benign (apocrine mixed tumor with intravascular tumor deposits) Yaakub 2012 60 F Nasal ala 1 Smooth firm bluish 10-mm nodule NP Benign (recurrent CS) Abil 2012 65 F Cheek 1 Well-defined rounded nodule of firm consistency, painless, adhering to the skin, measuring 3 cm in long axis, flesh-colored, with an irregular and telangiectatic surface NP Benign Walls 2012 68 F Eyebrow 1 1-cm firm mobile flesh- colored nodule NP Benign (recurrent) Araújo 2012 31 F Scalp (occipital area) 1 Hardened ulcerated lesion in the occipital region, with deep plane infiltration and elimination of tenuous purulent secretion NP Malignant (local invasion of cranium and occipital lobe) Su 2012 64 F Vulva 1 Solitary round-to-oval, non-tender mobile mass (measuring 2.1×1.0×0.8 cm) NP Benign Arango-Duque 2012 27 F Nose 1 Papular exophytic firm, well-defined lesion, 0.4 cm in diameter with some superficial telangiectasia NP Benign Bahrami 2012 0.5-84 4 M, 6 F Limbs, Trunk, Head 10 NP NP Benign Jun 2012 55 F Right malar area 1 Slowly growing subcutaneous mass NP Benign (apocrine type with calcification) Siraj 2012 59 M Scalp 1 Gradually enlarging non-tender cystic tumor NP Benign (with prominent pilomatricomal differentiation) Table 3. List of Publications Included in This Systematic Review. (continued) Review | Dermatol Pract Concept. 2024;14(4):e2024237 13 Author Year Age Sex Site Cases Clinical Morphology Dermoscopy Histology Franco 2013 68 F Second left toe 1 Voluminous nodular lesion with smooth erythematous surface, telangiectasias NP Benign Kumar 2013 27 M Upper eyelid 1 Firm, non-tender, sub- cutaneous, and not fixed to underlying tissues (1.5 x 1.5 cm) Erythematous background and telangiectatic vessels Benign Requena 2013 82 M Glabella 1 Subcutaneous area of swelling NP Malignant Hernandez 2013 40 M Medial calf 1 4.0 cm firm mass NP Benign Palioura 2013 53 F Upper eyelid 1 Asymptomatic “cystic” lesion NP Benign Kau 2013 71 F Upper eyelid 1 Firm painless polypoidal mass with superficial telangiectatic vessels and ulcerations ( 4.0×3.0×2.4 cm) NP Benign Whittle 2013 49 F Index finger 1 Slowly-enlarging painless focal subcutaneous mass NP Benign Malik 2013 61 F Scalp 1 Giant ulcero-fungating ulcerated growth NP Malignant (invasion of dural meninges) Tural 2013 34 F Nasolabial region 1 Slow-growing subcutaneous nodular lesion NP Malignant Boyaci 2014 55 M Elbow 1 Slow-growing painless mass NP Benign Nangia 2014 24 M Forehead 1 1 cm in diameter, firm nontender nodule NP Benign (extensive osseous differentiation) Paraskevopoulos 2014 53 M Left medial canthus 1 1 cm in diameter exophytic nodule NP Benign Wollina 2014 71 M Flank 1 Subcutaneous firm nodule NP Benign Choi 2015 58 M Nasal dorsum 1 Movable soft mass with elevation of the normal- appearing skin NP Benign Park 2015 84 F Nose 1 Soft cylindrically shaped protruding nodule with telangiectatic vessels Arborizing vessels and white shiny streaks Benign Krishnamurthy 2015 41 M Helix 1 Skin-colored nodular lesion NP Malignant (nodal metastasis) Menéndez 2015 63 F Epigastrium 1 Subcutaneous nodule NP Malignant (spinal cord) Kelten 2015 78 F Breast skin 1 Non-tender mobile, palpable lump localized superficially NP Benign Mahindra Nayyar 2015 33 M Cheek 1 1.8 x 1.3 cm reddish firm deep-seated nodule on the right medial cheek NP Malignant Table 3. List of Publications Included in This Systematic Review. (continued) Table 3 continues 14 Review | Dermatol Pract Concept. 2024;14(4):e2024237 Author Year Age Sex Site Cases Clinical Morphology Dermoscopy Histology Sereflican 2015 64 M Breast 1 12 x 9.8 cm non-tender firm polylobulated nodule covered by normal skin NP Benign Phelps 2015 63 F Eyelid 1 Slow-growing mass NP Benign (apocrine differentiation) Limaiem 2015 26, 45, 50, 38 F, F, F, M Lower eyelid, Nasogenien groove, Nose, and Chin 4 Slow-growing painless firm subcutaneous nodule NP Benign Aoun 2015 NP 5 M, 5 F Limbs, Face 10 NP NP Benign Shobhanaa 2016 57 F Scalp (occipital region) 1 Firm-to-hard, fixed to the underlying structures, and measuring 3 × 3 cm in their maximum dimension with a few tiny satellite nodules of 2–3 mm diameter. NP Malignant Odhav 2016 19 M Preauricular region 1 Firm fixed non-tender subcutaneous nodule NP Benign Ka 2016 53 M Axillary region 1 Invasive 10 cm mass NP Malignant Charles 2016 77 M Eyebrow 1 Subtly elevated nontender faintly erythematous subcutaneous mass with eyebrow madarosis NP Benign Madi 2016 47 F Plantar aspect of left foot 1 Tender mobile subcutaneous mass with overlying intact skin NP Benign Peria 2016 47 M Tip of the nose 1 Firm mobile nodule measuring 2 × 2 cm, covered by skin NP Benign Ismail 2016 74 F Nasal alar 1 Exophytic cystic mass with occasional superficial telangiectasia and a violaceous hue NP Benign Matsuyama 2016 26-85 6 F, 10 M Face, Nose, Scalp, Back 16 NP NP Benign Rogers 2016 67 F Axilla 1 Solitary well-demarcated extremely firm freely mobile non-tender subcutaneous nodule NP Benign (cytology) Azari-Yam 2016 68 F Upper eyelid 1 0.7 cm firm freely moving non-tender nodule NP Benign (apocrine differentiation) Shalini 2017 45 M Thigh 1 Firm non-tender lesion NP Benign (cytology) Alfonso Fernández 2017 49 F Finger (thumb) 1 1-cm diameter painful nodule NP Benign (invading the distal phalanx of the thumb) Laxmisha 2017 68 M Ear lobe 1 Solitary firm asymptomatic 2 × 2-cm skin-colored nodule NP Benign Table 3. List of Publications Included in This Systematic Review. (continued) Review | Dermatol Pract Concept. 2024;14(4):e2024237 15 Author Year Age Sex Site Cases Clinical Morphology Dermoscopy Histology Prieto-Granada 2017 42 F Upper back 1 NP NP Benign (with tyrosine-rich crystalloids) Turhan-Haktanir 2017 11 M Ala of the nose 1 Hard fixed 13 × 10 mm mass NP Benign Khotiya 2017 51 F Thigh 1 NP NP Malignant (with lung metastasis) Hudson 2017 41 M Lower Eyelid 1 Non-tender multilobulated firm freely movable mass NP Benign Sundling 2017 43 M Foot 1 Firm nodule/mass NP Benign Park 2017 46 F Cheek 1 Slow-growing nodular protruding mass NP Benign Fernandez-Flores 2017 81 M Scalp (above the hairline) 1 Subcutaneous mobile 1.2 cm nodule, which was apparently cystic, NP Malignant Nguyen 2017 52 F Thumb 1 Slow-growing nodular lesion associated with mild pain NP Malignant (local recurrence after 20 years) Jain 2018 70 F Lower eyelid 1 0.5 cm × 0.5 cm nodular non-tender swelling (preoperative diagnosis: sebaceous cyst) NP Benign (with cystic change and syringometaplasia) Nakanishi 2018 44 M Fingertip 1 Subcutaneous painless swelling (1 cm in diameter) NP Malignant An 2018 41 M Nose 1 Painless well-defined subcutaneous or intradermal nodule NP Benign Masamatti 2018 65 F Finger 1 Well-circumscribed mass measuring around 3 cm in diameter NP Benign Rogalski 2018 24 M Nose 1 Firm non-tender 7-mm skin-colored papule with telangiectasias NP Benign Lal 2018 86 M Left scapula 1 Pink indurated plaque NP Malignant Chauvel-Picard 2018 32 F Right eyebrow 1 Palpably mobile subcutaneous nodule NP Malignant Agrawal 2018 32 M Forehead 1 Firm painless mobile 5 mm x 5 mm nodule NP Benign Lu 2018 72 M Third toe of his right foot 1 Firm mass (2.3 × 1.5 × 1.2 cm) NP Benign Russel-Goldman 2019 32-88 15 M, 10 F Head and neck, Trunk, Limbs 25 NP NP Benign: 16 Apocrine, 9 Eccrine Nel 2019 78, 72 M, F Scalp, Thigh 2 1) Fungating mass with central ulceration (4.0 × 3.6 × 1.2 cm); 2) Hard mobile mass with protruding component (maximal diameter of 8 cm) NP Malignant Table 3. List of Publications Included in This Systematic Review. (continued) Table 3 continues 16 Review | Dermatol Pract Concept. 2024;14(4):e2024237 Author Year Age Sex Site Cases Clinical Morphology Dermoscopy Histology Owen 2019 19, 41 F, M Upper eyelid, preauricolar cheek 2 1) 5.5 x 4.5 cm firm painless freely mobile tumor; 2) 14 x 9.9 cm pedunculated firm painless freely mobile keloid-like lesion NP Atypical CS, Benign giant CS Panagopoulos 2019 61 M Delto- pectoral fold 1 Tender growing lump NP Malignant Linares González 2020 48 M Nasogenian sulcus 1 Nodular lesion (1 cm in diameter) with a smooth pearly surface Mimicking basocellular carcinoma: irregular telangiectatic vessels associated with cotton-white structures on an erythematous- white bed Benign Favareto 2020 60 F Knee 1 2 cm painful nodular mass NP Malignant (nodal metastasis) Mittal 2020 19 F Cheek 1 Multinodular mass of about 4 cm × 3 cm size with a subcutaneous swelling NP Atypical CS Wernham 2020 53 M Posterior heel 1 4 cm ulcerated exophytic nodule NP Benign Zia 2020 84 M Arm near axilla 1 9 × 7 cm subcutaneous nodule NP Malignant Rosell-Díaz 2020 74 M Scalp 1 Well-circumscribed polylobed nodule NP Benign Panagopoulos 2020 59, 60 M, M Thigh, Ankle 2 NP NP Benign Ki 2020 54 F Axilla 1 1 cm-sized oval hypoechoic mass NP Benign Okay 2021 53 M Right middle finger 1 a 3.5 -3 cm well- circumscribed firm lesion NP Benign Purkayastha 2021 7 M Left cheek 1 Firm lesion with blue discoloration and a surrounding area of hypervascularity NP Benign Vázquez Hernández 2021 65 M Upper lip 1 Chronic indolent subcutaneous tumor NP Benign Agarwal 2021 52, 71, 47 F, M, F Nose, postauricular region, nose 3 Progressively growing swelling NP Benign He 2021 47 M Lateral canthus 1 Well-demarcated asymptomatic dermal-based 0.9 cm nodule NP Benign (with pilomatrical differentiation) Table 3. List of Publications Included in This Systematic Review. (continued) Review | Dermatol Pract Concept. 2024;14(4):e2024237 17 Author Year Age Sex Site Cases Clinical Morphology Dermoscopy Histology Palit 2021 42 M Upper lip 1 Solitary 1 × 1 cm firm non-tender skin-colored-to- erythematous nodule Structureless area, milia-like cyst, irregular brown blotches, erythematous rim at the periphery and linear curved vessels Benign Petrovic 2022 88 F Right gluteal region 1 Subcutaneous mass NP Atypical CS (with diffuse nuclear expression of the p16 stain) Gotoh 2022 56 M Lower lip 1 Non-tender slightly hard mobile mass measuring ~11 x 11 x 7 mm NP Benign O’Rourke 2022 42, 58, 72 M, M, M, Eye canthus 3 Soft mobile nodules NP Benign Bal 2022 26 M Upper lip 1 Smooth-surfaced firm pedunculated nodule measuring approximately 1.1 cm in diameter Pleomorphic globules and irregularly enlarged branching telangiectasias conferring a marbled appearance Benign (with focal areas of ossification) Ungureanu 2023 73 F Fifth finger 1 Two contiguous nodules with a solid whitish appearance NP Benign Prajapati 2023 58 M Upper eyelid 1 Recurrent CS after surgery NP Benign Miranda 2023 77 M Right cheek 1 Subcutaneous nodule, color of the skin, with multiple telangiectasias, multilobulated, firm. NP Malignant (with cerebral metastasis) Kisova 2023 58 F Upper lip 1 Firm mass on the upper lip measuring 10/8/7 mm NP Benign Ferragina 2023 76, 53 F, M Orbital cavity, lip filter 2 1) non-tender multilobulated firm slightly painful mass2) non-tender well-defined mobile nodule of about 10 mm NP Benign Di Guardo 2023 28 F Philtrum 1 Firm non-tender mobile nodule, which was 1.2 cm in diameter Crown of dilated vessels, white structures (“cotton area”), erythematous background, and milia-like cyst Benign CS =chondroid syringoma; F = female; M = male; NP = not published Table 3. List of Publications Included in This Systematic Review. (continued) 18 Review | Dermatol Pract Concept. 2024;14(4):e2024237 46%), with the foot and sole being the most frequent site (20/50). The head and neck region accounted for 38% of cases (19/50), with 15 cases were reported on the scalp. Ad- ditionally, eight cases were noted on the trunk skin (16%), and two cases were found on multiple sites (4%). The me- dian maximum diameter of MCS lesions was 4.0 cm, with a size range of 0.7 to 19 cm. The most common clinical sub- type observed was a deep subcutaneous mass with intact overlying skin (19/47; 40.43%), followed by firm superficial nodules (15/47; 31.91%) and protruding or fungated masses (8/47; 19.15%). Five records presented with evident infiltra- tive lesions (10.64%). Ulceration was reported in eight cases (17.02%), while giant masses (≥8 cm) were observed in 14 cases (29.79%). No dermoscopic descriptions were reported. Regarding metastatic spreading, nine cases of distant metas- tasis were reported at the time of diagnosis (19.15%). The most common sites of organ metastasis were the lung and pleura (6/9), followed by the brain (4/9), bones (3/9), and liver (2/9). Other locations included the spinal cord (1/9), kidney (1/9), and thyroid (1/9). Nodal metastasis at the time of diagnosis was found in 14 cases (29.79%). Out of the 47 listed cases, 27 patients presented with no metastasis at the time of diagnosis (57.45%). Regarding records of local recurrence, it was found in nine cases (19.15%), while MCS with obvious features of local invasion were reported in five cases (10.64%). Discussion Chondroid syringoma (CS) stands as an exceptionally rare mixed tumor originating from sweat glands within the skin, characterized by histopathological features reminiscent of both glandular and cartilaginous tissues. Despite its infre- quency, it garners attention due to its unique nature, ac- counting for less than 0.2% of all diagnosed skin tumors. Predominantly, CS manifests as a solitary painless firm-to- hard nodule predominantly localized in the head and neck re- gion, notably on the nose, cheek, and upper lip. Nevertheless, occurrences have been documented across various anatom- ical sites, including the trunk, genital area, and extremities. Contributing to the expanding literature on CS, a recent case involves a 28-year-old woman with no significant medi- cal history presenting with a gradually enlarging lump on her left nasolabial fold, consistent with the clinical profile of CS. Dermoscopic examination revealed unique features such as the “signet ring” pattern. Subsequent histopathological anal- ysis confirmed the lesion as a benign chondroid syringoma, with negative surgical margins. A systematic review of the existing literature identified 347 unique cases of CS, with the majority classified as be- nign (83.6%). The clinical characteristics observed in these cases were consistent with previous descriptions, with a predilection for the head and neck region and a median age of diagnosis around the fifth decade of life. Interestingly, the review highlighted variations in clinical morphology, with a spectrum ranging from superficial nodules to deep subcu- taneous masses. Dermoscopic descriptions, albeit sparse, disclosed patterns like the “white-cotton” area and telan- giectatic vessels. While benign CS predominates, malignant cases constitute a notable subset (14.4%), underlining the significance of accurate diagnosis and management. MCSs may exhibit distinct clinical features, including larger size, more frequent occurrence on the limbs, and a considerable propensity for metastasis, notably to the lung, pleura, and brain. Distant metastasis was observed in a significant pro- portion of cases at diagnosis (19.15% of cases), highlighting the aggressive nature of this variant. Dermoscopy has become a valuable diagnostic adjunct for many skin cancers, although dermoscopic patterns in CS remain poorly documented. Recurrent features, such as whitish structureless areas and telangiectasias, are frequently observed. Additional features like milia-like cysts, erythema- tous homogeneous areas, and bluish homogeneous areas are also noted. Unique presentations, including a “marble-like” appearance, pigmented blotches, and a “signet ring” of ves- sels, further complicate specific dermoscopic pattern identifi- cation. Understanding these dermoscopic presentations aids in diagnosing mixed tumors of the skin. It is not possible to define pathognomonic dermoscopic patterns for chondroid syringoma due to the paucity of case reports. However, re- current features can be found. Whitish structureless areas and telangiectasias are observed in almost all cases described in the literature [9,10,11,12]. In addition, milia-like cysts, erythematous homogeneous areas, and bluish homogeneous areas are also recurrent features [11,1]. However, unique dermoscopic presentations such as marble-like appearance, pigmented blotches, and crown of dilated vessels must be considered [10,11]. These rare presentations make it more challenging to identify specific dermoscopic patterns that are useful for diagnostic purposes. In the case of mixed tu- mor of the skin, dermoscopy also predicts the histological composition [11]. The white structureless area corresponds to the fibrous stroma, the erythema to the increased vascu- larity, and the blue color represents a dominant chondroid stroma. The dermoscopic feature of milia-like cyst, which corresponds to the dermal keratocyst, points to the follicular- sebaceous-apocrine origin of the tumor. The main dermo- scopic differential diagnoses included basal cell carcinoma, nodular hidradenoma, trichoepithelioma, pilomatricoma, and sebaceoma. On dermoscopy, nodular hidradenoma ap- pears as a homogeneous area with varying colors, including white, along with other variable structures. The color of ho- mogenous areas varies from pinkish, bluish, and bluish-pink to brown. The associated vascular structures are arborizing Review | Dermatol Pract Concept. 2024;14(4):e2024237 19 telangiectasias, polymorphous atypical vessels, and linear irregular vessels [13]. The most recurrent dermoscopic fea- tures of pilomatricoma are red‐blue background with yellow structureless areas, and ulceration with linear irregular or tortuous or polymorphous vessels [14]. The dermoscopic picture of a trichoepithelioma demonstrates shiny white areas/background and milia-like cysts along with small thin in-focus arborizing vessels [13]. The most common dermoscopic features of sebaceoma are yellow structures (homogenous structureless areas and/or yellowish round- ish) with peripheral and thin arborizing or polymor- phous vessels  [14]. Occasionally, central whitish areas and pigmented structures can be found. Despite the potential of dermoscopy, histopathological examination remains the gold standard for CS diagnosis. Given its frequent occurrence in cosmetically sensitive areas, such as the face, identifying clinical features and dermoscopic patterns to differentiate benign CS from malignant coun- terparts holds clinical significance, potentially facilitating preoperative diagnosis. In cases of malignant CS, wide local excision stands as the most effective initial treatment, likely due to the presence of microscopic satellite nodules [15, 16]. Standard excisions without wide margins are associated with higher rates of local tumor recurrence and metastasis. Given the infiltrative nature of the tumor and the presence of satel- lite nodules, Mohs micrographic surgery is likely a promising treatment option and should be considered [17]. Lastly, this review aimed to augment our understanding of the clinical spectrum of CS, emphasizing the necessity for comprehensive diagnostic approaches and tailored manage- ment strategies. Given the rarity of CS, collaborative efforts between clinicians, pathologists, and dermatologists are im- perative for optimal patient care. Limitations This review is subject to some limitations. Firstly, the rarity of CS precludes the existence of prospective studies analyz- ing these tumors. Consequently, the analysis in this review is predominantly based on case reports and case series, which inherently limits the generalizability of findings. Variability in the detail and completeness of the available information across publications posed challenges in data interpretation. Additionally, the lack of uniformity in reporting standards hampered a thorough analysis and underscores the necessity for larger-scale studies to enhance our comprehension of this rare skin neoplasm. Conclusion In conclusion, cutaneous chondroid syringoma (CS) remains a rare yet clinically significant entity within the spectrum of skin tumors. Despite its infrequency, understanding its clin- ical presentation, histopathological features, and potential for malignant transformation is paramount for accurate di- agnosis and management. Dermoscopy emerges as a valu- able adjunct in diagnosing CS, although further research is needed to establish definitive dermoscopic patterns. Treat- ment primarily revolves around wide local excision, with Mohs micrographic surgery offering promising outcomes, especially in cases of malignant transformation. Collabora- tion between clinicians, pathologists, and dermatologists is essential for optimal patient care. While this review provides valuable insights into CS, future studies encompassing larger cohorts are warranted to address existing knowledge gaps and to enhance our understanding of this rare skin neoplasm. References 1. Villalón G, Monteagudo C, Martín JM, Ramón D, Alonso V, Jordá E. Siringoma condroide: revisión clínica e histológica de ocho casos [Chondroid syringoma: a clinical and histological review of eight cases]. Actas Dermosifiliogr. 2006 Nov;97(9): 573-7. Spanish. DOI: 10.1016/s0001-7310(06)73468-8. PMID: 17173760. 2. Stout AP, Gorman JG. Mixed tumors of the skin of the salivary gland type. Cancer. 1959 May-Jun;12(3):537-43. DOI: 10.1002 /1097-0142(195905/06)12:3<537::aid-cncr2820120313>3.0 .co;2-n. PMID: 13652101. 3. Yavuzer R, Başterzi Y, Sari A, Bir F, Sezer C. Chondroid syringoma: a diagnosis more frequent than expected. Dermatol Surg. 2003 Feb;29(2):179-81. DOI: 10.1046/j.1524-4725.2003.29045.x. PMID: 12562350. 4. Bates AW, Baithun SI. Atypical mixed tumor of the skin: histologic, immunohistochemical, and ultrastructural features in three cases and a review of the criteria for malignancy. Am J Dermatopathol. 1998 Feb;20(1):35-40. DOI: 10.1097/00000372-199802000 -00007. PMID: 9504667. 5. Min KH, Byun JH, Lim JS, Lee HK, Lee WM, Joo JE. 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Chondroid syringoma with os- teoma cutis. JAAD Case Rep. 2022 Jan 31;22:2-4. DOI: 10.1016 /j.jdcr.2022.01.023. PMID: 35242977; PMCID: PMC8886313. 11. Palit A, Sethy M, Nayak AK, Ayyanar P, Behera B. Dermoscopic features in a case of chondroid syringoma. Indian J Dermatol Venereol Leprol. 2021 Jan-Feb;87(1):89-92. DOI: 10.4103/ijdvl .IJDVL_167_20. PMID: 32969355. 12. Park SM, Ko HC, Kim BS, Kim MB, Mun JH. Large protrud- ing telangiectatic nodule on the nose. Clin Exp Dermatol. 2015 Jun;40(4):460-2. DOI: 10.1111/ced.12511. Epub 2014 Dec 5. PMID: 25476592. 13. Zaballos P, Gómez-Martín I, Martin JM, Bañuls J. Dermoscopy of Adnexal Tumors. Dermatol Clin. 2018 Oct;36(4):397-412. DOI: 10.1016/j.det.2018.05.007. Epub 2018 Aug 16. PMID: 30201149.