Malignant melanoma of the gallbladder: a report of two cases and review of the literature.

Melanoma metastatic to the gallbladder is rare. When present, it is often part of a widespread complex of metastases. Primary gallbladder melanomas are also extremely rare and can sometimes be difficult to distinguish from metastatic lesions. The optimal treatment for malignant melanoma of the gallbladder remains unclear, and prognosis is generally poor. We present here two cases of patients with metastatic lesions to the gallbladder. One patient presented with symptomatic cholelithiasis and was found incidentally to have a metastasis. Another patient had known a metastasis, but underwent curative resection of the only site of disease. We review the published literature for gallbladder melanoma, both primary and metastatic to determine the role of surgery in this disease.