Metastatic Melanoma of the Gallbladder in an Asymptomatic Patient

Malignant Melanoma (MM) is among the most dangerous malignancies with some of the least known survival rates. Melanoma most commonly metastasizes to regional lymph nodes, the lungs, and brain. Metastatic disease of the gallbladder (GB) is exceptionally rare making it difficult to diagnose. The fact that typically patients do not present until they are symptomatic—only after widespread metastatic disease has already occurred—is further complicating the diagnosis of MM of the GB. For this reason, MM of the GB is rarely discovered in living patients. In fact, review of the literature showed only 40 instances in which metastatic disease of the GB was reported in living patients. We describe the presentation and management of a patient who had metastatic disease of the GB. However, our case is unique because his malignancy was discovered incidentally while he was asymptomatic. He was successfully treated with an open cholecystectomy. We have presented this case in order to make the necessity of meticulous investigation of potential metastasis in patients with a known history of cutaneous melanoma clear.