Abstract
A 71-year-old man who had epigastric pain was referred to our hospital because of gastric wall thickening and leukocytosis (39,600/μl). Upper gastrointestinal endoscopy revealed gastric cancer, but the cause of the leukocytosis was unknown. He had no apparent source of infection, had hemodyscrasia, and his granulocyte-colony stimulating factor (G-CSF) level was abnormally high (415.9 pg/ml). A G-CSF producing gastric cancer was suspected and surgery was performed. A partial hepatectomy was needed because of hepatic infiltration but lymph node metastasis was not found. The mass was an undifferentiated carcinoma histologically and positive cells were detected on immunohistochemical staining. Postoperatively, the G-CSF level dropped to normal and the leukocyte count improved. These effects confirmed the diagnosis of a G-CSF producing gastric cancer. The patient is alive 2 years postoperatively and recurrence-free ; however, patients with G-CSF producing gastric cancers usually have a poor outcome.
