Primary bone lymphoma: Case report and review of the literature

Primary bone lymphoma (PBL) is a rare extra nodal manifestation of non-Hodgkin lymphoma, representing less than 5% of primary bone tumors. Diffuse large B-cell lymphoma (DLBCL) is the predominant histologic subtype, whereas indolent variants, including follicular lymphoma, are infrequently reported.

We present three cases of PBL, each illustrating distinct clinical, radiological, and pathological features. The first patient, a 54-year-old woman, presented with progressive left knee pain and swelling. Imaging revealed an extensive osteolytic lesion in the distal femur with soft tissue extension. Histopathology confirmed DLBCL of the germinal center B-cell (GCB) subtype.

The second case involved a 54-year-old man with chronic bilateral iliac pain. Pelvic CT demonstrated well-circumscribed osteosclerotic lesions in both iliac wings. Biopsy and immunohistochemistry confirmed primary bone follicular lymphoma, an indolent and rare PBL subtype.

The third patient, a 39-year-old woman, presented with recurrent right-sided basi-thoracic pain. Imaging identified a solitary osteolytic lesion in the posterior aspect of the sixth rib. Histopathology confirmed DLBCL.

These cases emphasize the heterogeneity of PBL presentations, highlight the critical role of early biopsy for accurate diagnosis, and illustrate the value of a multidisciplinary approach in patient management.