Dermatology: Practical and Conceptual Letter | Dermatol Pract Concept 2020;10(3):e2020051 1 Dermatology Practical & Conceptual Introduction Oculocutaneous albinism (OCA) is a group of autosomal recessive disorders characterized by defective melanin biosyn- thesis due to full or partial reduction in tyrosinase activity, which results in congenital depigmentation or hypopigmen- tation of the hair, skin, and eyes despite the normal number of melanocytes. In OCA, reduced or absent protection of melanin leads to sensitivity to ultraviolet radiation and a predisposition to skin cancers. Dermoscopic features of mel- anoma in patients with OCA have been reported in a few case studies. Here we report dermoscopic findings of an invasive melanoma arising from nevus in a patient with OCA. Case Presentation A 32-year-old female patient with OCA1 presented with a cutaneous lesion that had been enlarging for about a year. She stated that there was an asymptomatic pinkish plaque existing since childhood at the same location. The patient had hypomelanotic skin, blonde hair, blue-gray irides, and bilateral nystagmus. Dermatological examination revealed multiple pinkish papules surrounding a main central tumoral lesion over the right forearm (Figure 1). Dermoscopy of the lesions showed central yellow to orange structureless areas, central hemorrhagic crust, a peripheral arrangement of large yellow to orange clods and structureless areas, and polymor- phous vessels including linear, curved, and complex looped vessels (Figure 2). An incisional biopsy was made with prelim- inary diagnoses of cutaneous sarcoidosis, leishmaniasis, and cutaneous lymphoma. Histopathological examination of the incisional biopsy specimen revealed epidermal consumption, superficial dermal mononuclear inflammatory infiltration, a few bland-looking dermal nevus nests, and atypical melano- cytic infiltration filling the lower half of the papillary dermis and reticular dermis with numerous mitoses, including atypi- cal ones. No maturation was observed. Breslow thickness was 2.3 mm. Immunohistochemically, tumor cells were stained with HMB-45, Melan-A, and S-100 (Figure 3). A diagnosis of amelanotic nodular melanoma was made and a total excision with 2-cm margins was performed. No lymph node involve- ment and metastasis were detected. Conclusions Melanomas in patients with OCA are rare and usually amela- notic. Unfamiliar clinical and dermoscopic findings may cause diagnostic delay, which is usually associated with poor prog- Dermoscopy of Amelanotic Melanoma in a Patient With Oculocutaneous Albinism Belkis Uyar,1 Ömer Faruk Elmas,1 Asuman Kilitçi,2 Murat Tad2 1 Department of Dermatology and Venereology, Ahi Evran University, Kirşehir, Turkey 2 Department of Pathology, Ahi Evran University, Kirşehir, Turkey Key words: oculocutaneous albinism, melanoma, dermoscopy Citation: Uyar B, Elmas ÖF, Kilitçi A, Tad M. Dermoscopy of amelanotic melanoma in a patient with oculocutaneous albinism. Dermatol Pract Concept. 2020;10(3):e2020051. DOI: https://doi.org/10.5826/dpc.1003a51 Accepted: February 23, 2020; Published: June 29, 2020 Copyright: ©2020 Uyar 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. Authorship: All authors have contributed significantly to this publication. Corresponding author: Ömer Faruk Elmas, MD, Department of Dermatology and Venereology, Faculty of Medicine, Ahi Evran University, Kirşehir 40000, Turkey. Email: omerfarukmd@gmail.com https://doi.org/10.5826/dpc.1003a51 mailto:omerfarukmd@gmail.com 2 Letter | Dermatol Pract Concept 2020;10(3):e2020051 References 1. Peralta R, Sabban EC, Friedman P, et al. Proposal for management and dermosco- py follow-up of nevi in patients affected by oculocutaneous albinism type Ia. Der- matol Pract Concept. 2017;7(1):39-42. https://doi.org/10.5826/dpc.0701a07 2. Caldarola G, Fania L, Fossati B, et al. Dermoscopy of melanocytic lesions in patients affected by oculocutaneous al- binism: a case series. Dermatology. 2013;226(4):358-361. https://doi.org/10. 1159/000351315 linear vascular structures should prompt to exclude melanoma and other malig- nancies. Knowing the possible der- moscopic presentations of melanoma and the other tumors in patients with OCA may lead to early diagnosis and favorable prognostic outcomes. Age, location, ulceration, Breslow thickness, mitosis rate, and vascular invasion are the indicators of prognosis of melanoma in OCA as they are in any other type of melanoma. nosis. Furthermore, nevi in patients with OCA may have a similar dermoscopic pattern to that described for amelanotic melanoma [1]. Only a few studies have reported dermoscopic findings of melanoma in patients with OCA. Irregular dots, glob- ules, blue-white veil, peripheral arciform vessels, and milky red areas were the der- moscopic features reported in the study of Caldarola et al [2]. The present case had a different dermoscopic presenta- tion. A central core of orange structure- less areas surrounded by large yellow to orange clods and polymorphous vessels including linear, curved, and complex looped ones composed the main pic- ture. All previously described cases of amelanotic melanomas in patients with OCA predominantly demonstrated a polymorphous vessel pattern. Patients with OCA may have numer- ous pinkish lesions, and it can be very difficult to differentiate melanoma from benign lesions. In this context, dermo- scopic examination can be life-saving. Dermoscopic analysis in patients with OCA is mainly based on the vascular structures because of the lack of pig- mentation [1]. Pink nevi usually demon- strate only curved and comma vessels, while isolated lesions with dotted and Figure 2. (A) Handheld polarized dermoscopy shows central yellow to orange structureless areas, central hemorrhagic crust, peripheral arrangement of large yellow to orange clods and structureless areas, and (B,C) linear, curved, and complex looped vessels. Figure 3. Histopathological examination. (A) Epidermal consumption, superficial dermal mononuclear inflammatory infiltration, and atypical melanocytic infiltration (H&E, ×200). (B) High power shows malignant melanocytes (black circles), atypical mitosis (white cir- cle), and mononuclear inflammatory infiltration (blue circle) (H&E, ×400). (C) Diffuse staining with Melan-A (×200). (D) Bland-looking dermal nests indicating underlying nevus (H&E, ×400). Figure 1. Multiple pinkish papules sur- rounding a main central tumoral lesion over the right forearm. https://doi.org/10.5826/dpc.0701a07 https://doi.org/10.1159/000351315 https://doi.org/10.1159/000351315