Amputation neuroma mimics common hepatic duct carcinoma

Most amputation neuromas of the biliary tract occur in the cystic duct stum p after cholecystectomy and are asymptomatic. However, when they arise in t he main hepatic duct and are associated with obstructive jaundice, it is di fficult to distinguish them from carcinoma. We describe a case in which pre operative differential diagnosis was difficult. A 60-year-old man was admit ted to the Institute of Clinical Medicine, University of Tsukuba, with a ch ief complaint of jaundice. Cholangiography showed an irregularly elevated n odular lesion on the lateral wall of the common hepatic duct and multiple f loating stones in the choledochus. Ultrasonography and computed tomography revealed one-sided regional thickening of the common hepatic duct associate d with dilatation of the intrahepatic and extrahepatic bile ducts. Carbohyd rate antigen 19-9 level was markedly elevated to 11200 IU/mL in the bile ju ice, but was only 38 IU/mL in the serum, below the limit of abnormality. Ch olangioscopy showed papillary tumor with coarse granular surface mimicking papillary carcinoma, but biopsy revealed no malignancy. The patient underwe nt hepatico-choledochus resection. Although the macroscopic finding from th e surgical specimens was papillary carcinoma of the common hepatic duct pen etrating to the hepatoduodenal ligament, histopathological examination reve aled an amputation neuroma consisting of hypertrophic nerve tissues and gia nt cells containing foreign bodies, probably as a consequence of a previous cholecystectomy. The postoperative course was uneventful and the patient h as been living well for the 5 years since the resection.