plasma cell, a lymphoid or lymphocyte-like cell normally found in the bone marrow, the end stage of B lymphocyte maturation. On a Wright-stain marrow smear, plasma cells possess an eccentric nucleus with dark blue-staining chromatin arranged in a pattern like the spokes of a wheel. Plasma cells secrete immunoglobulins. Malignant plasma cells, called myeloma cells, are seen in bone marrow sheets and often in peripheral blood in multiple myeloma. See also B cell, multiple myeloma.
