The presence of a homogeneous immunoglobulin in serum and/or urine is a cardinal
point in the diagnosis of multiple myeloma. However, in an estimated 1 to 5% of cases,
a monoclonal spike cannot be identified. The term "nonsecretory" implies that a block in
release or synthesis accounts for the absence of paraproteinemia.
The authors experienced 2 cases of nonsecretory multiple myeloma studied by
hematologic, immunochemical and immunofluorescent methods. In case 1, the 74-year-old
male patient, the bone marrow aspiration and biopsy show immature and mature plasma
cells over 40% of the nucleated elements. Bence-Jones protein is negative. On
electrophoretic pattern, there is no monoclonal peak and immunoelectrophoretic study
reveals no abnormal precipitating arc. Immurofluorescence of bone marrow smears
demonstrates intracytoplasmic IgA, Lambda type M-component. In case 2, the
72-year-old female patient, the peripheral blood smears show ilnmature and mature
plasma cells over 25% of white blood cells and bone marrow aspiration and biopsy over
80% of the nucleated elements. Bence-Jones protein in urine is negative. There is no
monoclonal peak on electrophoretic pattern and no abnormal precipitating arc in
immunoelectrophoresis. Immunofluorescence of bone marrow smears demonstrates
intracytoplasmic IgA, Kappa type M-component.
So we report two cases of nonsecretory multiple myeloma (case 2 is associated with
plasma cell leukemia) with brief review of literature.
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