Intrahepatic cholangiocarcinoma coinciding with a liver metastasis from a rectal carcinoma: a case report

BACKGROUND: We experience many cases of liver metastasis from colorectal cancer, but synchronous occurrence of intrahepatic cholangiocarcinoma (ICC) and liver metastasis from a rectal cancer is extremely rare. We herein report a case of ICC coinciding with a liver metastasis from a known rectal carcinoma. CASE PRESENTATION: A 68-year-old man was referred to our hospital for investigation of multiple liver tumors. Total colonoscopy and computed tomography (CT) revealed a rectal carcinoma, coinciding with liver metastasis. He was planned to receive chemotherapy following rectal resection. During chemotherapy for the rectal cancer, one of the liver tumors gradually grew after first shrinking. The following hepatectomy revealed the presence of intrahepatic cholangiocarcinoma (ICC). Despite intensive chemotherapy for the ICC, he passed away 6 months after the hepatectomy. CONCLUSIONS: We should also suspect the possibility of multiple primary cancers, even if the patient has a history of cancer that is likely to cause metastatic lesions. When simultaneous neoplasms are diagnosed, systematic treatment should be targeted to the tumor with the worst prognosis.