Bone marrow aspirate from a 11 year-old, female-spayed, Dachshund. The patient was evaluated by her primary care veterinarian for chronically repeating nose bleeds. On bloodwork the patient was found to have a total protein of 11.8 g/dL (normal < 7.6 g/dL!). Only so many diseases cause such a marked increase in protein, so to they marrow they went…
Almost 50% of the cells in the bone marrow were these plasma cells (red arrow). Recall plasma cells are the lymphocyte variant that produce antibodies. And they have a GORGEOUS blue hued cytoplasm with a pearled center (the golgi zone). Often plasma cells will stick together - the thought is that all the antibody they are producing and have on their membranes sort of act like Velcro :-P 50% is WAY too many - <2% of your marrow cells should be plasma cells.
Diagnosis: Plasma cell myeloma! Which is almost synonymous with multiple myeloma. To diagnosis multiple myeloma your patient must have 2 of the 4: increase bone marrow plasma cells, monoclonal blood gammopathy, osteolytic lesions in bone, or antibody fragments in urine (the Bence-Jones proteins!) This poor dog also had the osteolytic lesions and monoclonal gammopathy. Prognosis is relatively good for a canine cancer, with a median survival of 1 year post-diagnosis.