A CASE OF MULTIPLE-MYELOMA PRODUCING GRANULOCYTE-COLONY-STIMULATING FACTOR

A case of multiple myeloma (IgA-lambda) with marked granulocytosis, wh ich measured up to 9.9x10(4)/mm(3), is described. Matured neutrophiles were predominant and blasts were not found in the peripheral blood. T he serum granulocyte colony-stimulating factor (G-CSF) was notably ele vated. The disease ran a chronic course and granulocytosis and elevate d serum G-CSF continued. The patient developed atelectasis and broncho pneumonia, and died of respiratory failure. At autopsy, bone marrow sh owed marked myeloid hyperplasia in varying states of differentiation. The enlarged spleen also disclosed numerous myeloid cells of varying d ifferentiation. Small aggregations of atypical plasma cells were prese nt in the marrow and spleen. Immunohistochemically, atypical plasma ce lls were positive for anti-G-CSF antibody, which indicated G-CSF secre tion from the myeloma cells. To our knowledge, this is the first repor ted case of G-CSF-producing multiple myeloma.