Cranial nerve palsy as the presenting feature of secondary plasma cell leukemia

A patient with IgA lambda multiple myeloma (MM) developed plasma cell leukemia (PCL), presenting as oculomotor nerve palsy. The cerebrospinal fluid (CSF) contained plasma cells, which double stained with fluoresceinated anti-IgA and anti-lambda antisera. The palsy was most probably due to meningeal myelomatosis. The neurologic disorder appeared to be refractory to the therapy used, although plasma cells disappeared from the peripheral blood. Secondary plasma cell leukemia is a rare complication of MM, usually occurring in the terminal stage of the disease. Those patients may be eligible for central nervous system (CNS) prophylaxis, as is commonly performed in patients with other types of leukemia.