Multiple metastatic malignant melanoma presenting intraluminal gallbladder bleeding

We report a case of malignant melanoma of unknown primary origin presenting metastasis in various organs as well as intraluminal gallbladder bleeding due to gallbladder metastasis. A 58-year-old woman was diagnosed with stage IV metastatic malignant melanoma. Because she exhibited acute cholecystitis and hemobilia due to malignant melanoma of the gallbladder, laparoscopic cholecystectomy was performed to relieve the symptoms. The resected gallbladder specimen showed a pedunculated black mass indicating malignant melanoma. Pathologic examination and immunohistochemical analysis revealed malignant melanoma of the gallbladder. Only a few cases of gallbladder malignant melanoma presenting hemobilia have been reported; here we present our case, including the experience of multidisciplinary treatment.