Signet ring-like light chain myeloma with systemic spread.

The morphological presentation of malignant plasma cells in multiple myeloma (MM) varies from mature to anaplastic plasma cells with only one reported case of signet ring variant. We describe here another case of signet ring-like lambda light chain MM associated with extra-skeletal spread to lymph nodes, spleen and liver. The clinical and pathological presentations were atypical with no evidence of bone-lytic lesions or monoclonal component on protein electrophoresis, leading to a delay of several years in the diagnosis. Recognition of this morphological entity of MM may help in an early diagnosis of this rare variant.