Papillary carcinoma of the common bile duct. Diagnosis by bile drainage cytology

A 54-year-old man with clinical and radiologic findings suggestive of pancreatic carcinoma had cytologic examination of bile drainage fluid specimens prepared by membrane filtration and cytocentrifugation. Examination showed clumps of malignant cells with features most consistent with a well-differentiated papillary neoplasm of bile duct origin, rather than a primary pancreatic carcinoma. Partial pancreatoduodenectomy with resection of the proximal common bile duct confirmed the presence of a small, well-differentiated but invasive papillary bile duct carcinoma. Pancreatic carcinoma and papillary carcinoma of the bile duct are anatomically and biologically different lesions that should be distinguished, when possible, by cytologic examination. In this case, surgical treatment was planned on the assumption that cytologic examination could distinguish a papillary carcinoma of the bile duct from the clinically suspected pancreatic adenocarcinoma.