Multiple Myeloma

Multiple Myeloma

Aspirate from the spleen of a 9-year-old neutered male Labrador. On ultrasound, the spleen appeared heterogeneous with focal hypoechoic nodules. Laboratory findings revealed a mild anemia, mildly increased liver enzymes, and a serum globulin concentration >7 g/dL.

The spleen was aspirated and submitted for evaluation. This image of the splenic aspirate consists of a moderate amount of peripheral blood surrounding numerous plasma cells. These plasma cells consist of a variable amount of lightly basophilic cytoplasm that occasionally exhibits a pink cytoplasmic border (flame cells), a prominent perinuclear clear area, and an eccentric round to oval nucleus with coarsely clumped chromatin. Anisokaryosis and anisocytosis are mild to moderate.

The definitive diagnosis is a plasma cell tumor. With the concurrent hyperglobulinemia, a high clinical suspicion for multiple myeloma is warranted. The next logical diagnostic steps are serum protein electrophoresis (to confirm the hyperglobulinemia is clonal) and radiographs looking for typical ‘punched-out’ areas of cortical bone.