Ectopic G-Csf Production by Malignant Plasma Cells in Patients with Diagnostic Criteria of Chronic Neutrophilic Leukemia

Chronic Neutrophilic Leukemia (CNL) is a relatively uncommon myeloproliferative neoplasia. Its diagnosis is based on the exclusion of the possible causes of neutrophilia altogether by the laboratory findings. The ectopic production of G-CSF by pathological plasma cells is well known in the medical literature. We present the case of a 77 year old woman fulfilling the diagnostic criteria of CNL. We verified G-CSF production by her pathological plasma cells using cellular separation techniques and PCR. The purpose of this paper is to communicate another case of the uncommon association between myeloma and neutrophilia, and reinforce the necessity of ruling out the existence of an underlying monoclonal gammopathy when a patient presents with CNL-like symptoms.