DOI: 10.36347/sjmcr.2015.v03i04.004

Pages: 296-300

Primary lymphoma of bone is the malignant lymphoid infiltrate within the bone without the evidence of lymph node enlargement or other tissues. Primary bone lymphomas are rare, even though in systemic lymphomas secondary involvement of the bone marrow is common. Differential diagnoses for primary bone lymphomas include Ewing’s sarcoma, chronic osteomyelitis, primary bone sarcoma, leukemic infiltrate, metastatic sarcomas, and carcinoma. Lymphomas can be misdiagnosed as Ewing’s sarcoma. We report a case of 22 years old male, who had a fall from bike and presented with pain in the left hip. On examination, there was tenderness over head of femur with no obvious swelling. Laboratory investigations revealed normal blood counts with increased serum LDH and C - reactive protein (i.e. 601U/L and 60.43 mg/L, respectively). CT scan revealed lytic sclerotic lesion in head and neck of left femur and MRI showed diffuse area of altered marrow signal intensity involving left femoral head, metaphysis as well as diaphysis. Histopathological examination of biopsy from left femur were suggestive of small round cell tumor probably Ewing’s sarcoma with Chronic osteomyelitis. Further, Immunohistochemical stains on paraffin- embedded tissue showed that the neoplastic cells were positive for LCA, CD20; while CD99 was equivocal. The neoplastic cells were negative for CD3, CD34 and cytokeratin. Thus, after correlating histopathological features and immunohistochemical profile, final diagnosis was given as high-grade Non- Hodgkin’s lymphoma; B- cell type showing nodular pattern. Primary Bone lymphoma is a rare but distinct clinico-pathological entity.