A case of renal melanoma metastasis: Description of clinico-pathological features

We report a case of single renal metastasis from skin melanoma revealed 14 months after observation and treatment of the primary tumor. A 63-year-old male patient presented with macroscopic intermittent hematuria for two months and right lumbar and inguinal pain. He had a history of previously treated skin melanoma. PET showed abnormal recurrence activity to right kidney, confirmed by the CT scan. Radical right nephrectomy was performed. Pathological examination revealed a high mitotic index of anaplastic neoplasm with epitheloid and fusiform atypical melanocytic cells with profuse cytoplasmic melanin pigment and immunohistochemical staining positive for HMB45. Surgery provided complete symptomatic relief, but at 3 months re-staging, CT total body, showed a lung metastasis. Patient refused standard systemic chemotherapy/immunotherapy and was treated with sunitinib. At 6 months disease progression was observed.