DERMATOLOGY PRACTICAL & CONCEPTUAL www.derm101.com Research | Dermatol Pract Concept 2012;3(1):7 25 Background Eccrine poroma (EP) is a relatively common benign adnexal neoplasm that is of eccrine origin. EP commonly occurs on the soles and lateral aspects of the feet, but it can also be found on other anatomic sites. It appears more frequently in adults. The most common clinical presentation is a firm nodule, from pink to red in color, sometimes slightly pedun- culated, measuring up to 2 cm in diameter. Sometimes EP presents as a small papule or as a verrucous plaque. Occa- Dermoscopy of non-pigmented eccrine poromas: study of Mexican cases Ana Elena Domínguez Espinosa1, Blanca Carlos Ortega2, Ricardo Quiñones Venegas3, Roger González Ramírez4 1 Hospital General de Zona 8, Gilberto Flores Izquierdo, Instituto Mexicano del Seguro Social, Mexico City, Mexico 2 Hospital de Especialidades, Centro Médico La Raza, Instituto Mexicano del Seguro Social, Mexico City, Mexico 3 Instituto Dermatológico de Jalisco, Guadalajara, Mexico 4 Servicios Médicos, U.A.N.L., Monterrey, Mexico Key words: dermoscopy, eccrine poroma, polymorphous vascular pattern Citation: Domínguez Espinosa AE, Carlos Ortega B, Quiñones Venegas R, González Ramírez R. Dermoscopy of non-pigmented eccrine poromas: study of Mexican cases. Dermatol Pract Conc. 2013;3(1):7. http://dx.doi.org/10.5826/dpc.0301a07. Received: September 5, 2012; Accepted: November 8, 2012; Published: January 31, 2013 Copyright: ©2013 Domínguez Espinosa et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Funding: None. Competing interests: The authors have no conflicts of interest to disclose. All authors have contributed significantly to this publication. Corresponding author: Ana Elena Domínguez Espinosa, Calzada General Anaya 338, Col del Carmen Coyoacán cp. 04100, Mexico City, Mexico. Tel. +52 (55) 56328385; Fax. +52(55) 24583961. Email: anaelenad@yahoo.com.mx. Background: Eccrine poroma is a benign neoplasm that can mimick a malignant neoplasm dermo- scopically. The characteristic vascular pattern of this tumor has not been established. Objective: To evaluate dermoscopic features of non-pigmented eccrine poroma in Mexican patients. Method: We retrospectively studied histologically proven cases of eccrine poroma from three Mexican hospitals analyzed by four dermoscopists. Results: Thirteen cases were studied. A polymorphous vascular pattern was found in most cases. Four presented with irregular linear and branched vessels with semi-elliptical, or semicircular endings (“chalice-form” and “cherry-blossoms” vessels). Structureless pink-white areas were the most com- mon other dermoscopic finding. Conclusions: “Chalice-form” and “cherry-blossom” vessels have not been reported in other benign or malignant neoplasms and can be a useful clue to the diagnosis of non-pigmented eccrine poroma. Due to the variability of dermoscopic patterns of eccrine poroma further studies are required to estab- lish the specificity of our findings. ABSTRACT 26 Research | Dermatol Pract Concept 2012;3(1):7 cific clues or patterns of non-pigmented EP have not been established. The aim of this study was to evaluate dermoscopic fea- tures of non-pigmented EP in Mexican patients and to com- pare our findings with those already published. Material and methods This is a retrospective study, including histologically veri- fied cases of non-pigmented EP examined by dermoscopy, in three different Mexican hospitals with polarized and non- polarized dermoscopy (DermLite pro HR and DermLite Hybrid M; 3 Gen, Dana Point, CA, USA). The photographs were taken with a Nikon Coolpix P5100. All cases were ana- lyzed with polarized light with and without immersion; for contact dermoscopy we used common cleansing gel alcohol. All cases were photographed with and without immersion with minimum pressure on the tumor. Each dermoscopic image was evaluated independently by four dermoscopists for the presence of vascular pattern and additional clues. sionally EP can be pigmented. Usually it is a solitary tumor. When multiple lesions appear on palms and soles the condi- tion has been termed eccrine poromatosis [1,2]. Dermatopathologically it is a proliferation arising from the lower portion of the epidermis from where it extends into the dermis forming a mass or broad anastomosing bands, composed of epithelial cells with uniform cuboidal appearance with round basophilic nuclei, connected by intercellular bridges. In the majority of cases, small ducts and occasionally cystic spaces are found within the aggrega- tions of tumor cells [3]. Dermoscopy is a non-invasive technique that is useful for the diagnosis of benign and malignant melanocytic and non-melanocytic lesions. In general the presence of a poly- morphous vascular pattern is considered to be a useful clue to differentiate between benign and malignant neoplasms. Vascular patterns, including morphology and distribution of vessels, can be useful to make a specific diagnosis, especially in combination with other structures. However, only a few articles describe the dermoscopic features of non-pigmented EP [4-7]. Since the number of published articles is small, spe- TABLE 1. Dermoscopic structures Patient Sex/Age Anatomic site Hair pin vessels Linear irregu lar vessels Chalice- form/cherry blossoms Structureless pink-white areas Milky-red/ lacu na-like areas Ulceration Glomerular vessels 1 F/63 thigh - - +/+ - - + - 2 F/82 upper arm + - +/- + + - - 3 M/49 foot - - +/+ + - - - 4 M/44 back - - - + + - - 5 F/35 foot + + - + - - - 6 M/41 foot + - +/+ + - + - 7 M/36 foot + - - + +* - + 8 M/78 abdo- men - - - + + - - 9 F/46 foot - + - + + + - 10 M/63 foot - - -/+ - +* - + 11 M/57 foot - - - - +* - - 12 F/48 foot - - - - +* - - 13 F/46 trunk + + - + +* - - Number 5 3 4/4 9 9 3 2 Percentage 38% 23% 30% 70% 70% 23% 15% Research | Dermatol Pract Concept 2012;3(1):7 27 The dermoscopic features are presented in Table 1. We found no differences with regard to dermoscopic structures seen with polarized light with immersion and polarized light without immersion. Nine cases (70%) showed a polymor- phous vascular pattern, including at least two types of vas- cular structures; four of them (30%) showed irregular linear vessels with a semi-elliptical ending giving the appearance of a chalice (“chalice-form”). In addition to “the chalice-form” vessels, three cases (23%) also showed structures combin- ing thin branching vessels with circular and semicircular tips, very similar to the structure of the cherry blossom tree; and, in addition, one of these displayed a small ulceration (Figures 1, 2, 3). One more case showed “cherry-blossom” vessels in the center of the lesion and milky-red globule/ lacuna-like areas surrounded by pink-to-white halo (“frog- egg” aggregations) in the periphery. Four more cases (in total Results We included 13 cases of 4 women and 7 men. The mean age was 53 years (range 35—82). All patients were Mexican with Fitzpatrick’s phototype skin III and IV. None of them had medical histories of importance for the present illness. Only two patients reported pruritus and two reported pain during walking. Eight cases were located on the feet. The remaining cases were located on the arm, thigh, abdomen, back and lateral aspect of the trunk. Clinically the lesions presented as pink-to-red nodules, as nodules with a keratotic plug, and as a warty, papillated plaque. The average diameter was of 12 mm (range 5-20 mm). The lesions developed to their current size within 1 to 15 years. The clinical differential diagnoses included kerato- acanthoma, clear cell acanthoma, larva migrans, amelanotic melanoma and squamous cell carcinoma. Figure 1. Case 1. Immersion polarized dermoscopy shows the chal- ice-form and cherry blossom vessels (arrows) and small ulceration (cross). [Copyright: ©2013 Domínguez Espinosa et al.] Figure 2. Case 3. Polarized dermoscopy without immersion showing cherry-blossom, chalice-form vessels (arrows), and structureless pink- white areas (cross). [Copyright: ©2013 Domínguez Espinosa et al.] Figure 3. Case 6. Immersion polarized dermoscopy. Cherry-blossom, chalice-form (thin arrows) hairpin vessels (thick arrows), structure- less pink-to-white areas (cross). [Copyright: ©2013 Domínguez Es- pinosa et al.] Figure 4. Case 11. Polarized dermoscopy without immersion. Frog- egg aggregations (arrows) and central lacuna-like area (cross). [Copyright: ©2013 Domínguez Espinosa et al.] 28 Research | Dermatol Pract Concept 2012;3(1):7 characteristic of non-pigmented EP in of our series, were also found in most cases in the study of Ferrari et al [6]. The well-circumscribed milky-red lacunas separated by white- pink bands, the “frog-egg” appearance, which were seen in five (38%) of our patients, were also found in 30% of cases studied by Minagawa et al [9]. Conclusion The “chalice-form” and “cherry-blossom” vessels are a good clue for the diagnosis of non-pigmented EP, although, for unknown reasons, the pattern of non-pigmented EP is not uniform, and further studies are required to establish the specificity of our findings. References 1. Taylor S, Perone J, Kaddu S. Appendage tumors and hamartomas of the skin. In: Wolff K, ed. Fitzpatrick’s Dermatology in General Medicine. 7th ed. USA: McGraw Hill, 2008: 1069-87. 2. Calonje E. Tumours of the skin appendages. In: Burns T, ed. Rook’s Textbook of Dermatology. 8th ed. Oxford, UK: Wiley- Blackwell, 2010:53.1-53.44. 3. Elder D, Elenitsas R, Bernett J, et al. Tumors with eccrine differ- entiation. In: Elder D, ed. Lever’s Histopathology of the Skin. 9th ed. Philadelphia, USA: Lippincot Williams & Wilkins, 2005:898- 910. 4. Avilés-Izquierdo JA, Velázquez-Tarjuelo D, Lecona-Echevarria M, Lázaro-Ochaita P. [Dermoscopic features of eccrine poroma.] Article in Spanish. Actas Dermosifilogr 2009;100(2):133-6. 5. Blum A, Metzler G, Juergen B. Polymorphous vascular patterns in dermoscopy as a sign of malignant skin tumors. A case of an amelanotic melanoma and a porocarcinoma. Dermatology. 2005;210(1):58-9. 6. Ferrari A, Buccini P, Silipo V, et al. Eccrine poroma: a clini- cal-dermoscopic study of seven cases. Acta Derm Venereol. 2009;89(2):160-4. 7. Nicolino R, Zalaudek I, Ferrara G, et al. Dermoscopy of eccrine poroma. Dermatology. 2007;215(2):160-3. 8. Aydingoz IE. New dermoscopic vascular patterns in a case of ec- cine poroma. J Eur Acad Dermatol Venereol. 2009;23(6):725-6. 9. Minagawa A, Koga H, Takahashi M, Sano K, Okuyama R. Dermoscopic features of nonpigmented eccrine poromas in as- sociation with their histopathological features. Br J Dermatol. 2010;163(6):1264-68. 10. Suzaki R, Shioda T, Konohana I, Ishizaki S, Sawada M, Tanaka M. Dermoscopic features of eccrine porocarcinoma arising from hidroacanthoma simplex. Dermatol Res Pract. 2010:192371. 30%) show these “frog-egg” aggregations (Figure 4) and the rest of the cases combined linear irregular, hairpin vessels in addition to milky–red globules-like areas. In nine cases (70%) a structureless pink-to-white area was found, the most frequently found non-vascular structure. The dermatopathologic findings were typical for eccrine poroma. All lesions were formed of cuboidal basophilic cells arranged in anastomosing broad bands with small ductal spaces in contact with the epidermis and extending onto the dermis. Some cases show pseudocystic spaces with mucous stroma. The capillaries were dilated and filled with eryth- rocytes. Since all the samples were cut vertically, we could not carry out any other histological analysis of the vascular morphology. Discussion Eccrine poroma can mimic malignant tumors, including amelanotic melanoma, which emphasizes the importance of characterizing the dermoscopic patterns of non-melano- cytic lesions. Altamura et al were the first to publish dermoscopic characteristics of a case of non-pigmented EP. Since then 22 additional cases have been reported. All reported cases had a polymorphous vascular pattern [4,6-9]. This pattern is characterized by the presence of irregular vessels that vary in size and shape and by the combination of different types of vessels. The vascular pattern of cases reported by Aydingoz [8] was described as “floral and leaf-like.” We propose to call these vessels “chalice-form” and “cherry-blossom ves- sels” because of their similarity with a chalice and because the branches resemble the flowers of cherry trees. We con- sider these terms easy to remember. These vascular patterns seem to combine hairpin and branched vessels and have not been reported as part of the vascular pattern of melanoma or other malignant tumors [5,10]. Therefore, the presence of this vascular pattern could be a helpful clue in differen- tiating EP from other benign or malignant non-pigmented neoplasms. However, given the small number of cases in our study, it would be premature to consider these vessels spe- cific for eccrine poroma. Although in other studies glomerular, arborizing and lin- ear irregular vessels were dominant, we barely found them in our series. Structureless pink-to-white areas, a dominant