Alpha-fetoprotein-producing carcinoma of the colon: report of a case.

We report herein the rare case of a 67-year-old man in whom alpha-feto-protein (AFP)-producing carcinoma originated in the transverse colon, describing the clinical course of the patient and the histological features of the tumor. At the age of 63, the patient had been diagnosed as having sigmoid colon carcinoma, and surgery was carried out. However, 4 years later, his fecal occult blood test was positive, and further investigation revealed a transverse colon carcinoma with liver metastasis. The serum AFP measured preoperatively was 10978 ng/ml. Resection of the transverse colon and a liver biopsy were performed, following which his serum AFP level decreased to 4804 ng/ml. Histology of the ulcerated lesion in the transverse colon showed a poorly differentiated adenocarcinoma with a medullary growth pattern. Using an immunohistochemical staining method, AFP-producing cells were detected in the transverse colon carcinoma and the liver metastasis. Based on our experience of this patient and a review of the literature on the few cases previously reported, we conclude that AFP-producing coloretal carcinoma has a tendency to produce blood-borne metastasis and to be associated with a poor prognosis.