Pseudo-Auer rods in a patient with newly diagnosed IgG myeloma.

A 83-year-old woman with chronic gastrointestinal problems developed retinal vein thrombosis. Laboratory tests revealed an erythrocyte sedimentation rate of 45, renal dysfunction (GFR 25 mL/min), and mild anemia (hemoglobin 10 G/dL) with normal white cells and platelets. 2-microglobulin was elevated at 8.06 mg/L. A plasma cell dyscrasia was suspected and immunoglobulin testing showed monoclonal IgG, in the serum (28.9 g/L) with free chains (1.2 g/L), and light chains in the urine (10.2 g/L). Bone marrow aspirate contained 10% plasma cells (CD38 CD138 ) with long, slender, Auer-like inclusions (see figure) in 50% of the cells. Approximately 14% of the plasma cells had multinuclear forms.