Acral lentiginous melanoma with subsequent spontaneous vitiligo vulgaris: a case report and literature review

Acral lentiginous melanoma (ALM) is an infrequent and often missed subtype of melanoma. Its association with spontaneous vitiligo vulgaris is an exceedingly rare condition. The current study presents a rare case of ALM with spontaneous vitiligo vulgaris after complete resection of the ALM. An 84-year-old male patient presented with multiple white skin lesions on the scalp, neck, trunk, and upper and lower limbs for a three-month duration. One year prior, a diagnosis of ALM was confirmed on histopathological examination with a pathological stage of T4bNxMx. The patient did not receive any treatment until the time of presentation, apart from the surgical removal of the primary tumor. No treatment was advised for the patient's vitiligo vulgaris; only observation was recommended. Clinical diagnosis of vitiligo vulgaris was made based on the association with ALM. A review of the literature reveals that only a limited number of case reports have linked vitiligo to ALM, especially in cases where immunotherapeutic agents were not administered. Melanoma is a notably immunogenic malignancy, provoking both humoral and cellular immune responses directed against cytoplasmic and membrane antigens of melanocytes. It is suggested that normal melanocytes may function as neutral observers and become targets of immune responses directed against melanoma cells, leading to melanoma-associated vitiligo. It occurs more commonly as a consequence of immunologic-based therapeutic interventions or after metastatic melanoma; however, the occurrence of spontaneous vitiligo vulgaris several months following complete surgical removal of ALM is possible.