The production of colony-stimulating factors by thyroid carcinoma is associated with marked neutrophilia and eosinophilia.

Cancers producing colony-stimulating factors and associated with marked leukocytosis are relatively rare. We report here a case of a thyroid cancer producing both granulocyte colony-stimulating factor (G-CSF) and granulocyte-macrophage colony-stimulating factor (GM-CSF). A 72-year-old woman had a thyroid carcinoma with significant neutrophilia and eosinophilia without any evidence of infection. The serum concentrations of both G-CSF and GM-CSF were elevated significantly in this patient, which might have induced the leukocytosis. Furthermore, the G-CSF concentrations in thyroid tumor tissue and metastatic lesions in the lung and skin examined at autopsy also were extremely high.