Eruptive Acral Melanocytic Lesions Associated With Capecitabine

Eruptive nevi and lentigines have been reported to occur in the setting of immunosuppression, which may be medication-induced. The associated histopathologic findings have not been well described in the literature. Herein, we report the case of a woman in her 60s who had been receiving chemotherapy treatment with capecitabine, a prodrug of 5-fluorouracil, for advanced pancreatic cancer. She developed multiple small, dark macules on the dorsal and plantar surfaces of both feet. An initial biopsy of one lesion showed a crowded lentiginous proliferation of predominantly single melanocytes, with poor nest formation and some pagetoid scatter. Subsequent biopsies revealed lentigines with melanocytic hyperplasia, which showed less cellularity than the initial biopsy. This case provides histopathologic correlation for eruptive acral melanocytic lesions that result from capecitabine therapy.