Systemic polyclonal immunoblastic proliferations

This report describes the clinical and pathologic features of four patients with a florid, systemic immunoblastic proliferation. The blood of these patients exhibited a mild to marked leukocytosis with a high percentage of immunoblasts and plasma cells. The bone marrow also was infiltrated extensively by immunoblasts. Lymph node biopsy specimens from two patients showed near total effacement of the nodal architecture by a diffuse infiltration of immunoblasts and plasma cells. The proliferative process was determined to be polyclonal with immunohistochemical techniques. Cytogenetic studies of bone marrow from two patients showed a pseudodiploid abnormal clone, with a translocation involving a break in band 14q32 in each case. The pathogenesis of these proliferative disorders in unclear, although three patients had some evidence of an acute immune disorder. One of these patients was treated with steroids, vincristine, and cyclophosphamide. Another patient was treated with steroids only, and one patient was treated with steroids and cyclophosphamide. All had rapid regression of the disease process. Two patients are alive and apparently free of disease 31 and 48 months after diagnosis. One died of sepsis. The fourth patient had acquired immune deficiency syndrome (AIDS) and died without therapy. The biology of the immunoblastic proliferation of these patients is uncertain. The immunohistochemical results suggest a reactive, polyclonal proliferation, but the cytogenetic abnormalities in two patients indicate the possibility of a cryptic neoplastic clone.