A Case of Simultaneous CA19-9-producing Gastric and Rectal Cancers

Abstract

A 72-year-old man visited our hospital because of epigastric pain. Computed tomography (CT) showed a slight amount of free air in the upper abdomen, but the epigastric pain tended to improve, and conservative treatment was started. The free air then disappeared on CT. Adenocarcinoma of the lower stomach was diagnosed by biopsy examination under gastroscopy, and perforated gastric cancer was thought to be the cause of the free air. In addition, adenocarcinoma of the lower rectum was diagnosed by biopsy examination under colonoscopy. The preoperative serum CA19-9 level was elevated at 5,525 U/ml. Distal gastrectomy, partial hepatectomy, and low anterior resection were performed. The postoperative serum CA19-9 level decreased to 488 U/ml. On immunohistochemistry, gastric cancer cells stained strongly positive for CA19-9. Based on the above, a CA19-9-producing gastric cancer was diagnosed. In addition, rectal cancer cells stained weakly positive for CA19-9.

There have been 45 reported cases of CA19-9-producing gastric cancers, including the present case, but there have been no reports of simultaneous CA19-9-producing gastric and rectal cancers, and this case is reported along with a review of the relevant literature.