B-cell Lymphoma in the guise of Multiple Myeloma

A very intellectually stimulating discussion of a 54 yo homeless M presenting with acute on chronic R hip pain. More detailed history-taking reveals constitutional symptoms of progressive fatigue, fever with sweats, polyuria and constipation. On evaluation, serum calcium level was 18.8 (after correction), AKI and on MRI+CT multiple bone lesions (spine, R hip) and a splenic lesion as well. Also had normal PTH and PTHrp but with elevated total 1,25 dihydroxy Vit D (indicating extra-renal production). Bone marrow showed high grade large B-cell lymphoma.

There is a case report very similar to our patient with lymphoma mimicking multiple myeloma in the pattern of bone marrow involvement. NEJM review article  of hypercalcemia with malignancy and management of hypercalcemia