A 60 year old man has a pathological rib fracture. He also complains of recurrent infection. BMA (bone marrow aspiration) is done. Labs: Ca2+ 3.9mmol/L and ALP 127u/L. what type of cell would be found in abdundance in the marrow smear?

The key is A. Plasma cell. [The diagnosis of multiple myeloma. i) age 60 yrs ii) pathological rib fracture (from metastases) iii) recurrent infection (due to B cell dysfunction (manifested as hypogammaglobulinemia), numerical and functional abnormalities of T cells, and dysfunction of natural killer cells), iv) raised calcium level.