RESUMO
A 17 years old boy presented with warm, tender and swollen joints of both upper and lower limbs along with inflammatory back pain and heel pain since 7 months. He had developed continuous high grade fever 3 days ago and complained of marked weight loss during the last 6 months. On examination his liver, spleen and cervical lymph nodes were palpable. X ray of the affected joints revealed osteolytic lesions in tibia, fibula, and humerus and fracture head of femur. Bone marrow examination revealed infiltration by sheets of lymphoid cells which were positive for leukocyte common antigen and CD[20]. The bone biopsy from a lytic lesion in proximal left tibia revealed a similar picture of infiltration with sheets of CD[20] positive lymphoid cells. Need to remember that lymphoproliferative disorders can mimic rheumatological disorders in clinical practice. The case is presented to share the experience of others