Solitary skeletal lesions as primary manifestations of non-Hodgkin's lymphoma. Report of two cases and review of the literature.

Two patients with solitary skeletal lesions of the lower extremity were eventually diagnosed as having high-grade malignant B-cell non-Hodgkin's lymphoma. In both cases staging revealed no other nodal or extranodal involvement. One patient had been symptomatic for more than 2 years, presenting originally as a case of chronic synovitis. The second patient presented with slight exertional pain in his left knee of relatively recent history. In his case the initial plain X-ray showed little evidence of bony destruction, while magnetic resonance imaging revealed an extensive lesion in the left tibial plateau. Orthopedic surgeons should be aware of the differential diagnosis of primary lymphoma of bone. Early use of magnetic resonance imaging, in addition to plain X-ray and scintigraphic imaging, can be helpful in leading to an early biopsy and consequently early treatment. Magnetic resonance imaging should be regarded as the method of choice for follow-up examinations of lymphoma lesions.