Primary B-cell lymphoma of bone in children

Primary lymphoma of bone (PLB) is a rare entity of extranodal non-Hodgkin lymphoma (NHL). We report on two children with PLB focussing on diagnostic evaluation and treatment strategy. Clinical and radiographic presentation in both children suggested a primary bone tumour such as Ewing sarcoma. A 13-year-old girl showed osteolytic tumours in the right 7th rib and right iliac crest. Additional skeletal lesions were found by whole-body positron emission tomography. A 6-year-old boy presented with an isolated, osteolytic lesion of the left distal femur. In both patients staging procedures excluded any organ involvement besides the skeletal tumours. Tumour biopsy and immunohistological studies revealed lymphoblastic non-Hodgkin lymphoma of B-cell lineage in both children. They received a polychemotherapy for B-cell lymphoma according to the NHL-BFM 95 protocol and are in complete remission with a follow up of 24 and 18 months respectively. Conclusion Isolated, primary lymphoma of bone in children may clinically and radiographically impose as primary bone tumour. Multiple therapeutic strategies have been applied in the treatment of this malignancy, however, treatment modalities are not well focussed on immunological patterns in the case of primary lymphoma of bone. Staging techniques should include immunophenotyping to initiate specific cell lineage treatment.