[A Case of Metastatic Liver Tumor from Colon Cancer with Preoperative Diagnosis Obtained by Immunohistochemical Analysis of Cytologic Specimen].

CASE: A woman in her 50s underwent sigmoid colectomy and D3 lymph node dissection for sigmoid cancer(pT3, N0, M0, Stage Ⅱ: Japanese Classification of Colorectal, Appendiceal, and Anal Carcinoma 9th). She received adjuvant chemotherapy with capecitabine. Seven months after surgery, contrast-enhanced computed tomography( CECT) scan revealed a small mass in the segment 2 (S2) of the liver with dilation of peripheral intrahepatic bile duct, and the size of this mass and the bile duct dilatation were gradually increased. FDG positron emission tomography(FDG-PET)/CT showed abnormal FDG uptakes in the lesion of S2, and EOB-MRI detected other small lesions in the S6 and S7. Considering the results of image examinations, multiple lesions intrahepatic cholangiocarcinoma was firstly assumed. However, immunohistochemistry of the tumor obtained by endoscopic retrograde cholangiopancreatography (ERCP) showed cytokeratin 7-negative. Based on preoperative diagnosis of liver metastasis from colon cancer rather than intrahepatic cholangiocarcinoma, we performed left lobectomy, partial hepatectomy of S6 and S7 and cholecystectomy. In the resected specimen, the tumor was macroscopically located in the intrahepatic bile ducts. Microscopically, there existed atypical epithelial cells with glandular duct-like structure, and the lesions was histopathologically diagnosed as metastasis from colon cancer. She was discharged on the 10th postoperative day, and she is alive without recurrence one year after surgery.