Melanoma Metastases Arising at Unexpected Sites: Gallbladder and Uterus

Although malignant melanoma (MM) most frequently tends to metastasize to the regional lymph nodes, liver, lung and brain, several unusual sites of metastasis have been described in the literature. Among these, the metastatic involvement of gallbladder or uterus represents an exceptional event, usually associated with diffuse metastatic disease or observed as an autopsy finding. In this paper, we present two unusual cases of isolated MM metastasis to these anatomic sites, arising in a 71-year-old man and a 54-year-old woman, for whom no information on previous malignancies was known at the time of the histological examination. The clinico-pathologic features are described, emphasizing that MM metastasis must be included in the differential diagnosis when dealing with patients with a previous diagnosis of MM and onset of a novel mass/lesion even at unusual sites