A CASE OF CHOLEDOCHAL CYST ASSOCIATED WITH ADENOCARCINOMA EXHIBITING SARCOMATOUS FEATURES

One complication of choledochal cyst in adulthood is the development o f secondary carcinoma, usually well-differentiated adenocarcinoma. We report a case of extrahepatic bile duct carcinoma associated with chol edochal cyst and presenting predominantly sarcomatous features. The pa tient was a 52-year-old female who presented with abdominal fullness a nd pain. Ultrasound (US), computed tomography (CT), and cholangiograph y revealed a choledochal cyst with a tumor. The resected choledochal c yst was 10 x 7.5 cm and contained a protruding, ulcerated tumor, measu ring about 4.0 x 2.5 cm. Histologically, the tumor was composed of spi ndle-shaped or fusiform cells with occasional pleomorphic or bizarre g iant cells and abundant fibrous stroma, similar to malignant mesenchym al tumors. However, further histologic and immunohistochemical examina tion revealed that the tumor was adenocarcinoma with prominent sarcoma tous features. To our knowledge, sarcomatous change in extrahepatic bi le duct carcinoma associated with choledochal cyst has not been previo usly described.