What happened, in summary

A 67-year-old man had no abdominal symptoms when a routine examination found a large mass near the stomach and spleen. CT showed a roughly 10-cm tumor between the spleen and the upper stomach, and endoscopy found an ulcerated gastric lesion. Biopsy identified adenocarcinoma. Imaging and surgery found no tumors in the liver, pelvis, small bowel or peritoneum.

He underwent tumor resection, subtotal gastrectomy, D2 lymph-node dissection and splenectomy because the mass had grown into the spleen. He recovered from the operation without complications. Pathology showed moderately to poorly differentiated gastric adenocarcinoma that penetrated the stomach wall and involved the spleen and omentum. Three of 23 lymph nodes contained cancer, and pathology classified the disease as Stage III.

Special tumor-marker staining supported the unusual germ cell tumor features. Examination of the testes did not find a separate testicular primary. He did not receive postoperative anticancer treatment. During 1 year of follow-up, there was no gastric-cancer recurrence or distant metastasis.