Metastatic melanoma presenting as malignant biliary obstruction of the common bile duct demonstrated with single-operator digital cholangioscopy

A 67-year-old woman with a history of malignant melanoma of the left flank, which was completely removed 2 years earlier, and gallbladder (GB) metastasis, which was removed by cholecystectomy 16 months earlier, presented with progressive jaundice and passage of melena for 2 months. Her vital signs were stable, but her hemoglobin had decreased from 11 to 6 g/dL. CT showed an enhancing intraductal mass 3.8 cm long at the distal common bile duct (CBD) causing upstream biliary dilatation (Fig. 1A). ERCP was performed (Video 1, available online at www.VideoGIE.org). Endoscopy showed bleeding from the ampulla. Cholangiography demonstrated a large, irregular filling defect at the distal CBD (Fig. 1B). Biliary sphincterotomy, followed by single-operator digital cholangioscopy (SpyGlass DS, Boston Scientific, Marlborough, Mass), demonstrated a large, irregular, brown mass inside the CBD (Fig. 1C). Each of 4 biopsy specimens was taken by 1.2-mm biopsy forceps (SpyBite, Boston Scientific) under direct visualization and by 2-mm biopsy forceps under fluoroscopy. Brushing cytology was not performed. Then, a self-expandable metallic stent (SEMS) was placed. Histopathologic examination of the specimens obtained by both types of biopsy forceps demonstrated pleomorphic, loosely cohesive cells with enlarged, hyperchromatic, and irregular nuclei of the tumor. The results of immunohistochemistry staining, including HMB-45 and Melan-A antigens, were both positive, which confirmed the diagnosis of metastatic malignant melanoma to the CBD (Figs. 1D-G). After the procedure, the patient’s jaundice was improved, and there was no further bleeding. Three months later, metastatic melanoma to the nasopharynx developed, and the patient underwent complete excision. After surgery, she refused chemotherapy. At a 1-year follow-up visit, she did not describe symptoms of recurrent bile duct obstruction. A CT scan showed only partially enhancing soft tissue at the distal CBD with a patent SEMS and aerobilia.

Metastatic melanoma to the GB and the CBD is extremely rare, with 10% reported on autopsy cases of malignant melanoma. We detected the metastasis of malignant melanoma to the CBD by using single-operator digital cholangioscopy. Although it is uncommon, the possibility of metastatic melanoma to the extrahepatic biliary tree should be excluded in patients presenting with obstructive jaundice who have a known history of malignant melanoma.