Dermatology: Practical and Conceptual Research Letter | Dermatol Pract Concept. 2024;14(3):e2024202 1 Similar Clinical and Dermoscopic Features of Cutaneous Schwannomas Gaye Güldiken Doğruel1, Güldehan Atış2, Pembegül Güneş3 1 İstanbul Arel University Faculty of Medicine, Ataşehir Memorial Hospital, Department of Dermatology, İstanbul, Turkey 2 Üsküdar University Faculty of Medicine, Ataşehir Memorial Hospital, Department of Dermatology, İstanbul, Turkey 3 Şişli Memorial Hospital, Department of Pathology, İstanbul, Turkey Key words: schwannoma, schwannomas, dermoscopy, epiluminescence microscopy, skin neoplasm Citation: Güldiken Doğruel G, Atış G, Güneş P. Similar Clinical and Dermoscopic Features of Cutaneous Schwannomas. Dermatol Pract Concept. 2024;14(3):e2024202. DOI: https://doi.org/10.5826/dpc.1403a202 Accepted: March 30, 2024; Published: July 2024 Copyright: © Güldiken Doğruel 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: Gaye Güldiken Doğruel, Ataşehir Memorial Hospital, Küçükbakkalköy, Vedat Günyol Cd. No:28-30, 34750 Ataşehir, İstanbul, Turkey. Tel: +905058675240, E-mail: gayeguldiken@gmail.com Introduction Schwannomas rarely present as isolated dermal lesions, and they are usually diagnosed by pathological examination [1]. In the literature, data on dermoscopy of cutaneous schwan- nomas are limited to a small number of cases. In this article, two schwannoma cases with very similar clinical features will be discussed in light of their dermoscopic findings. Case Presentations Two cases of histopathologically confirmed schwannoma with available clinical and dermoscopic photographs are pre- sented (Table 1). Both patients presented with asymptomatic skin-colored dermal nodules located on the face with prom- inent telangiectatic vessels to the naked eye. Polarized der- moscopy of the first case revealed a dermoscopic pattern of scattered slight brown pigmentation on a milky-red-whitish surface and arborizing and looped vessels on the periphery with light pressure. Polarized dermoscopy of the second case also revealed arborizing and prominent telangiectatic vessels crossing the midline and fine telangiectasias on a milky-red background (Table 1, Figure 1). Both tumors were surgically removed with the differential diagnoses of intradermal ne- vus, nodular type basal cell carcinoma, and skin appendage tumor. Histopathological examination revealed the diagno- sis of schwannoma. Written informed consent was obtained from both patients for the publication of clinical details and lesion images. Conclusion Schwannomas’ dermoscopic findings were not well de- scribed [1]. In the few case reports, nonspecific erythema [2], blue-white veil on structureless brown-blue pigmenta- tion [3], branching vessels of different diameters, scattered pigmented areas, lobulated appearance [4], and branching vessels on a whitish transparent background [5,6] have been described. Nonspecific erythema and structureless pigmenta- tion were observed in schwannomas that had existed for a 2 Research Letter | Dermatol Pract Concept. 2024;14(3):e2024202 relatively longer time (>20 years) [2,3], yet branching vessels were reported in newer lesions (6 months–8 years) [4-6]. The absence of vascular structures in older lesions may be due to degeneration of the lesion over time. In our cases, the reason why branching vessels were clearly visible on dermoscopy may be that they are relatively new lesions or that these le- sions were located just under the epidermis. Cutaneous schwannomas can be included in the differential diagnosis with malignant and benign lesions such as nodular basal cell carcinoma and intradermal nevus due to their clinical features and vascular structures in dermoscopy [6]. Kim et al. [6] stated that in their case series the appearance of arborizing vessels on polarized dermoscopy in half of the lesions could be a clue in narrowing down the differential diagnosis. We suggest that schwannoma should also be considered in the preliminary diagnosis of patients presenting with telangiectatic vessels evi- dent on macroscopy on a skin-colored dermal nodule. In suspi- cious lesions, histopathology is essential in diagnosis. Figure 1. Clinical pictures of (A) Case 1 and (C) Case 2 showing prominent telangiectasias. (B) Scattered light brown pigmentation on a milky-red-whitish surface with arborizing/looped vessels on the periphery with pressure (arrows) and (D) arborizing vessels on dermoscopy. (E, G) Encapsulated nodular lesion in the dermis separated from the surrounding area by a smooth border on histopathological examination. (F, H) Diffuse and strong staining with s100 in immunohistochemical examination. Table 1. Clinical and dermoscopic information Patient Age Sex Duration Location Clinical Features Tumor Size Symptom Dermoscopy 1 41 Male 3 years Right malar Skin-colored nodule with prominent telangiectatic vessels 5x4x3 mm - Scattered pigmentation on milky-red-whitish surface, arborizing/looped vessels on the periphery with pressure 2 45 Female 2 years Right perinasal Skin-colored nodule with prominent telangiectatic vessels 8x6x5 mm - Arborizing and prominent telangiectatic vessels crossing the midline, fine telangiectasias on a milky-red background with slight brown pigmentation Research Letter | Dermatol Pract Concept. 2024;14(3):e2024202 3 4. Daulatabad D, Pandhi D, Tanveer N, Sharma S, Kaur I. Solitary dome-shaped erythematous lump of long duration on the palm. Indian J Dermatol Venereol Leprol. 2018;84(4):437-439. doi:10.4103/ijdvl.IJDVL_845_16. 5. Joshi A, Thapa DP. Asymptomatic nodule on face: Dermoscopic and histopathological clue for diagnosis. NJNS. 2020;17(1): 63-65. 6. Kim DH, Mun JH. Dermoscopic Features of Schwannoma. Der- matol Pract Concept. Published online April 1, 2023. doi:10.5826 /dpc.1302a69. References 1. Rodríguez-Peralto JL, Riveiro-Falkenbach E, Carrillo R. Benign cutaneous neural tumors.  Semin Diagn Pathol. 2013;30(1): 45-57. doi:10.1053/j.semdp.2012.01.008. 2. Reyna-Rodríguez IL, Chavez-Alvarez S, Ocampo-Candiani J. Case for diagnosis. Infraorbital schwannoma. An Bras Dermatol. 2021;96(3):358-361. doi:10.1016/j.abd.2020.08.014. 3. Miyamoto K, Yanagi T, Maeda T, et al. Dermoscopic features of haemorrhagic schwannoma.  Australas J Dermatol. 2021; 62(2):e322-e323. doi:10.1111/ajd.13477.