Elevated granulocyte colony-stimulating factor, non-infectious leukocytosis and fevers in a patient with multiple myeloma.

Background: We report the case of a 56-year-old male with multiple myeloma in whom recurrent fevers and leukocytosis delayed potentially effective chemotherapy due to concern for active infection.

Design And Measurements: A thorough infectious workup, including CT and PET scans, was negative. The patient was eventually found to have an elevated serum granulocyte colony-stimulating factor (G-CSF) of 113 pg/ml (normal range 0.