Rodrigo César Davanço, Department of Dermatology, Heliópolis Hospital Complex, São Paulo, Brazil Rafael Amaro, Department of Dermatology, Heliópolis Hospital Complex, São Paulo, Brazil Domingos Jordão Neto, Department of Dermatology, Heliópolis Hospital Complex, São Paulo, Brazil Carolina Brandão Milanez, Department of Dermatology, Heliópolis Hospital Complex, São Paulo, Brazil Aline Sperandio Porto Rezende, Department of Histopathology, Heliópolis Hospital Complex, São Paulo, Brazil


Acral lentiginous melanoma is uncommon, representing about 4–6% of all melanomas that affect the Caucasian population, but it is the most frequent form of melanoma in Asian and African descendants, with a prevalence above 50%. Peak of incidence is around the sixth decade of life and affects both sexes equally. The etiology is uncertain, but it is suspected that local trauma and traumatic stress are part of the possible triggering factors. Onychomycosis, subungual hematoma, and striated melanonychia generated by a nevus in the nail matrix are part of the differential diagnosis.

 

We present the case of a young patient with melanonychia in the first right finger, with recent onset and progressive alteration, both in color and in the width of the melanonychia, whose histopathology confirmed the diagnosis of subungual melanoma in situ. A surgical approach with removal of the nail apparatus and conservation of the distal phalanx has been successful with no relapse after two years.



Keywords: Melanoma. MART-1 antigen. Nevi and melanoma.