RESUMEN
Adenosquamous carcinoma arising in congenital choledochal cyst is very rare and herein we report a case thereof. A 37-year-old woman was referred for further evaluation of pancreas head mass and a hepatic nodule on CT. She had been diagnosed with congenital choledochal cyst at 22-years-old and received Roux-en-Y choledochojejunostomy at that time. Endoscopic ultrasonography-guided biopsy proved the pancreas head mass as a squamous cell carcinoma and liver biopsy also proved the liver mass as a metastatic squamous cell carcinoma. We performed pancreaticoduodenectomy and tumorectomy of metastatic liver nodule. Grossly, the primary lesion was located at intrapancreatic portion of choledochal cyst. Histologically, the primary lesion and hepatic nodule was metastatic adenosquamous carcinoma. So far, there have been only three cases of adenosquamous carcinoma arising in congenital choledochal cyst reported in English-language literature. This is another case and the first case reported in Korea.