[A case of advanced gastric cancer growing extramurally with gynecomastia and high hCG-beta serum level].

We describe a rare case of advanced gastric cancer with markedly high serum levels of human chorionic gonadotrophin beta subunit (hCG-beta). The patient was a 51-year-old man admitted for a gastric tumor growing extramurally and multiple liver tumors revealed by computed tomography, with chief complaints of abdominal and breast mass. Upper gastrointestinal endoscopy showed gastric cancer of Borrmann type 2 and biopsy specimens showed poorly-differentiated adenocarcinoma. The serum levels of hCG/beta was very high (21, 551. 6 mIU/mL). Pathological examination from liver tumor showed the tumor cells greatly resembled gastric tumor and were immunohistochemically positive for hCG-beta. We diagnosed hCG-beta producing gastric cancer. He received chemotherapy, but died of hepatic failure about 8 months after initial diagnosis. When we see a patient with gynecomastia and the high serum hCG-beta levels, it is important that hCG-beta producing-gastric cancer should be considered as a possible malignant tumor of the stomach.