Squamous cell carcinoma of the cervix producing granulocyte colony-stimulating factor

Marked leukocytosis is occasionally observed in patients with a malignant nonhematopoietic tumor. Granulocyte colony-stimulating factor (G-CSF) may be responsible for this phenomenon. We report a case of G-CSF-producing squamous cell carcinoma of the cervix that showed marked leukocytosis.

A 71-year-old Japanese woman was admitted for further investigation for leukocytosis. Her white blood cell (WBC) count had been gradually increasing over a period of 10 months. Laboratory data on admission revealed marked leukocytosis, with a WBC count of 30,400/microL, which consisted primarily of mature granulocytes (93%). Her serum G-CSF level was significantly elevated. However, there was no evidence of infection or hematopoietic disorders. Further examinations showed stage IIIb cervical cancer. The pathological diagnosis was squamous cell carcinoma of the nonkeratinizing type. Immunohistochemical staining of the biopsied specimens confirmed the production of G-CSF protein by the tumor cells. The patient was successfully treated by radiation therapy. Her WBC count returned to a normal level (3,700/microL). Her serum G-CSF level also decreased. The patient is alive without evidence of recurrence at 8 months after the treatment.

It is suggested that the leukocytosis manifested in this patient was due to G-CSF produced by the tumor. It was possible to use the WBC count and serum G-CSF levels as additional tumor markers.