Fig. 2

Intraoperative and pathological findings. a Intraoperative photograph after laparotomy. The infiltrated site of the transverse colon was taped (arrowhead). b The surgical specimen showed infiltration of the transverse colon (arrowhead) by the tumor. c Macroscopic appearance of the sections of the liver (left) and the transverse colon (right) revealed that the tumor was solitary and whitish, 8.5 × 7.5 cm in diameter, and had irregular margin. The dark-red lesion (*) was cavernous hemangioma. Direct invasion to the transverse colon was detected (arrowhead) d Hematoxylin–eosin staining of the tumor in the liver (Liver, × 40), transverse colon (T/C, × 40), and lymph node in the transverse mesocolon (LN, × 20) revealed glandular structures and a tendency toward keratinization. Therefore, we concluded that the tumor included an adenocarcinoma component as well as a squamous cell carcinoma component, suggesting ASC of the liver. e Immunostaining of the liver tumor revealed that the tumor was CK 7 (+) and CK 20 (−), indicating adenocarcinoma of the biliary system. The tumor was CK 5/6 (+) and p 40 (+), indicating that it also included a squamous cell carcinoma component (× 20)