A case of gastric carcinoma associated with excessive granulocytosis. Production of a colony-stimulating factor by the tumor.

A patient with gastric carcinoma exhibited an excessive granulocytosis (58,000/microliter) preoperatively, in the absence of overt infection. After resection of the primary tumor, the peripheral leukocyte count decreased promptly to the normal value. In a search for a colony-stimulating factor (CSF), the tumor was transplanted into nude mice. A marked neutrophilia was observed in the tumor-bearing mice, suggesting the production of CSF by the tumor. Media conditioned by the primary culture of the tumor cells revealed the presence of CSF activity as well. CSF-producing carcinomas have been detected in various organs; nevertheless, no cases of gastric carcinoma have hitherto been described. It is of particular interest that in this patient hypercalcemia was not observed, although it often accompanied CSF-producing tumors reported previously. Therefore, it is suggested that this tumor secreted pure CSF and that the CSF produced by the tumor did not necessarily induce hypercalcemia.