Bone lymphoma with multiple negative bone biopsies.

This article describes a 71-year-old man with right knee pain, prerenal azotemia, hypercalcemia, and a mass in the distal femur. Although testing, including bone marrow biopsy, initially ruled out myeloma, an open surgical biopsy eventually confirmed the diagnosis as lymphoma involving the bone with classic histologic findings of mature B-cell neoplasm of germinal cell origin.