A case of spindle and giant cell-type undifferentiated carcinoma of the extrahepatic bile duct.

Spindle and giant cell type undifferentiated carcinoma of the extrahepatic bile duct is an uncommon malignancy. We report a case involving the common bile duct in a 72-year-old male with jaundice who was admitted to our hospital. Diagnostic imaging, including abdominal computed tomography and magnetic resonance imaging, revealed a mass in the distal common bile duct, accompanied by dilatation of both intra- and extrahepatic bile ducts and regional lymph node enlargement. Endoscopic retrograde cholangiography demonstrated stenosis in the distal common bile duct, with a biopsy confirming adenocarcinoma. The patient underwent endoscopic retrograde biliary drainage followed by a subtotal stomach-preserving pancreaticoduodenectomy with regional lymphadenectomy. Microscopic examination revealed that the tumor predominantly comprised spindle and giant atypical cells within the stroma. Immunohistochemical analysis showed the tumor cells expressing cytokeratins and mesenchymal markers, confirming the diagnosis of spindle and giant cell type undifferentiated carcinoma of the common bile duct. Ki-67 labeling index was observed to be above 80%. Postoperatively, intra-abdominal lymph node recurrence was noted at two months, and multiple liver metastases were identified at three months. The patient died seven months post-surgery. The literature pertaining to this rare disease is reviewed and discussed.