Polyclonal systemic immunoblast proliferation: An unusual hematologic entity presenting as a medical examiner case

A 43-year-old woman who was receiving oral antibiotics for several days for a superficial foot infection developed a persistent rash, fever, and lymph adenopathy, despite discontinuation of the antibiotic and administration of steroids for a presumed drug reaction. Hours after a subsequent visit to t he emergency room for worsening symptoms, she died at home. Ac autopsy, the re was a florid, systemic proliferation of polyclonal plasma cells and immu noblasts infiltrating nearly every organ and tissue of the body, most notab ly the lymph nodes and spleen. The polyclonal nature of the process was con firmed by immunofixation electrophoresis and immunohistochemistry. Cases of fatal polyclonal systemic immunoblast proliferations are extremely rare: a nd the trigger for such proliferations is not always known. We review the l iterature on this unusual entity and discuss the clinical and pathologic fi ndings.