Diffuse plasmacytosis in a child with brainstem glioma following multiagent chemotherapy and intensive growth factor support

The use of granulocyte colony-stimulating factor (G-CSF) or granulocyte- macrophage-colony-stimulating factor (GM-CSF) in order to abrogate chemotherapy-induced neutropenia has become a routine part of many cancer treatment regimens. However, there are still very few data available about possible complications related to repeated or prolonged use of these agents in patients with malignant solid tumors. The authors report a child with brainstem glioma who received repeated cycles of multiagent chemotherapy with G- or GM-CSF support. During this period of 10 months, no clinical side effects were observed that could have been attributed to growth factor administration. However, postmortem histological examination revealed the presence of diffuse plasmacytosis, a rare hematological disorder in childhood. Undifferentiated plasma cells of nonmonoclonal origin could be demonstrated infiltrating bone marrow, lungs, and lymph nodes of the patient. Based on previously published in vitro and in vivo evidence on the interleukin-6 (IL-6)-mediated stimulatory effect of G- and GM-CSF on myeloma cell proliferation, the authors suggest a possible link between extensive growth factor support and the development of plasmacytosis in this patient.