Primary non-Hodgkin's lymphoma of bone: three cases and a short review of the literature.

Primary non-Hodgkin's lymphoma of bone (PLB) is a rare entity. We present three new cases and a review of the literature. If PLB is suspected radiologically, the diagnosis must be confirmed by open biopsy. Histopathologically, PLB usually represents diffuse large B-cell lymphoma or lymphoma of the follicular center type. The extent of local disease manifestation, additional skeletal involvement, and the presence or absence of lymphadenopathy is assessed by radiological examination. Localized stages of the disease require involved-field radiotherapy (45-50 Gy) to the entire bone that is affected. Regional lymphatics must also be irradiated. Radiotherapy may be required immediately to prevent pathological fractures. In the few cases of more widespread skeletal or extraskeletal involvement, radiotherapy of the major site of manifestation may be followed by a "watch-and-wait" strategy until progression of the disease becomes apparent. In cases of intermediate or high-grade lymphoma of bone, combined radiochemotherapy is the treatment of choice for all stages. Six to eight cycles of chemotherapy (usually the CHOP regimen) are recommended for remission induction. This is followed by involved-field radiotherapy with 45-50 Gy. High-dose chemotherapy with autologous stem cell support is an option if there is no satisfactory response to conventional chemotherapy, or if early relapse occurs.