Metastatic Anal Squamous Cell Carcinoma Presenting as an Indeterminate Biliary Stricture Diagnosed By Cholangioscopy.

Anal squamous cell carcinoma (SCC) rarely metastasizes outside the pelvis. Although liver involvement has been described, biliary strictures from metastatic disease are exceedingly rare. We report a case of a patient with metastatic anal SCC presenting as a biliary stricture, which was identified on endoscopic retrograde cholangiopancreatography with single-operator cholangioscopy. Direct visualization of the stricture with single-operator cholangioscopy may prove critical in obtaining a timely diagnosis. Therapeutic options for metastatic anal SCC are limited, but chemotherapy can be considered, and surgical resection is an option for limited disease.