Lymphoma of bone

Neoplasm is composed of malignant lymphoid cells (B cells, T cells, and rarely null cells), arising in persistent red marrow and producing a mass-like lesion in bone with or without involvement of local regional nodes. Primary bone lymphoma initially only involves bone, either at a single site or in multiple bones in the absence of supraregional or other extranodal diseases. Plasma cell neoplasms are excluded. There is a slight male predominance (from 1.3:1 to 1.8:1 in most studies). Most are adults over the age of 40 (mean is 40-65 in larger series). It can occur at any age (documented from 1.5 to 87 years). Red marrow of the long bones and axial skeleton is most frequently involved. Plain radiographs show a spectrum of changes varying from normal or minimal subtle changes to diffuse permeative destruction of the bone. Histologically a diffuse growth pattern is usual. Permeation of marrow spaces occurs, the cells surrounding and entrapping the host bone which usually remains otherwise intact. Residual marrow fat is also often present. Appropriate immunophenotyping is necessary in all cases for adequate clarifi cation. Current optimal treatment regimens for adults include combined chemotherapy and radiotherapy.