A 64 year-old WM presenting with fever, vasculitic rash and SOB was diagnosed with Chlamydia pneumoniae, cryoglobulinemia, polyclonal gammapathy and an abnormal plasma cell phenotype.

SPEP and IFE revealed polyclonal gammapathy. We analyzed bone marrow histology with flow cytometry of peripheral blood and bone marrow and obtained a skin biopsy for histology and immunofluorescence.

SPEP and IFE revealed polyclonal gammapathy. Bone marrow histology demonstrated increased plasma cells with lymphoplasmacytoid morphology more like that of lymphocytes than plasma cells and occasional binucleated plasma cells. Peripheral blood flow cytometry demonstrated a heteogenous population of mature B and plasmacytoid-like cells, appearing polyclonal. There was a population of polyclonal large cells expressing B cell and plasmacytoid cell markers, expressing CD 19 but not 20, composing 6% of WBC population. Bone marrow flow revealed similar findings. Chromosome analysis demonstrated no clonal abnormalities. Skin biopsy revealed vasculitis with perivascular lymphocytes and plasma cells around small blood vessels consistent with cryoglobulinemia. IgG, IgM and IgE were significantly elevated with elevated titers to C. pneumoniae. Qualitative cryoglobulins were positive. Imaging studies were significant for lung infiltrates, axillary and subcarinal lymph nodes, and soft tissue within the AP window.

The patient had findings usually associated with a monoclonal process but his abnormal plasma cell phenotype showed no evidence for clonality. The patient initially responded to prednisone but worsened as the drug was tapered. His rash and cryoglobulinemia resolved with hydroxychloroquine, suggesting a reactive process to infection. This phenotype, however, raises questions about abnormalities in regulation of plasma cell differentiation.