Hepatoid Adenocarcinoma of the Rectum With Liver Metastasis in a Patient With Ulcerative Colitis

Hepatoid adenocarcinoma (HA) is a rare malignant tumor of extrahepatic origin that morphologically and immunophenotypically resembles hepatocellular carcinoma. We report a case of rectal HA with hepatic metastasis arising in a 38-year-old male with a history of ulcerative colitis. Despite elevated alpha-fetoprotein, contrast enhancement of the hepatic mass was not consistent with hepatocellular carcinoma. Immunohistochemistry revealed the diagnosis, and the patient was started on palliative chemotherapy. Colorectal HA should be considered when evaluating malignant lesions in the setting of inflammatory bowel disease and can be distinguished from other tumors based on alpha-fetoprotein, imaging, and immunostaining.