Ewing’s sarcoma of the left femur initially treated as chronic osteomyelitis Hassan Elbahri, Yasir N. Gashi INTRODUCTION Ewing’s sarcoma is a rare small round cell sarcoma. It is occurs most often in bone. 1 Ewing’s sarcoma is a high-grade aggressive neoplasm with a poor prognosis if not treated. 2 Delay between symptom onset and diagnosis is common. In one study, 50% of patients had symptoms for more than 6 months before the tumor was diagnosed. 3 The most frequent initial misdiagnoses in older patients with ES were tendinitis (21%) and sciatica (11%) and, in younger patients, coxitis simplex (9%) and osteomyelitis (6%).4 Case report A nine years old girl presented with a huge swelling involving her left thigh for the last 4 months. She was quite well till 4 months ago when her mother noticed that she had a limp while walking. At that time there was no swelling. The patient was taken to the hospital where she was treated as having muscular pain with only simple analgesics. One month later she developed a swelling in the left thigh which was associated with mild fever. X-ray, U/S and CBC were done and a diagnosis of chronic osteomyelitis was made. I.V cefuroxime and surgical drainage was attempted. No pus was found, so multiple drill holes was made looking for an intramedullary collection and again nothing drained except an organized hematoma. Patient was deteriorating every day with more pain and more swelling. Parents took their own decision to seek medical advice in the principal hospital. Full clinical, laboratory and radiological workup was done once the patient received. There was a huge swelling in the left thigh extending from the hip down to the knee. The skin was shiny, tens with multiple dilated veins beside a surgical scar. CBC showed hypochomic anaemia. X rays showed intramedullary lesion at mid shaft femur with onion skin type of periosteal reaction and multiple drill holes on the cortex (fig.1). MRI showed an enhanced heterogeneous mass at shaft of the femur with soft tissue extension occupying antero- medial and lateral compartment, which raised a high suspicion of malignant tumour. (fig.2) Open biopsy was performed and histology revealed Ewing’s sarcoma. The tumour was extensive involving all the compartments and no chance was left available for limb salvage. Chemotherapy started and later left hip disarticulation was done.. CONCLUSION Ewing’s sarcoma is well known in literature that it has constitutional symptoms like fever and swelling and it mimic chronic osteomyelitis. Ewing’s sarcoma occurs predominantly in the below 20 years of age, and it considers as one of the most aggressive tumours 5. Several cases have been reported misdiagnosis of Ewing’s sarcoma as osteomyelitis. Reasons reported for the misdiagnoses include a low level of suspicion, occurrence at an atypical site, and the lack of or insufficient histologic specimens.6,7. In our case report the primary surgeon rely on his clinical judgment and has a low level of suspicion. The golden rule of biopsy what you culture and send a swab for culture for what you biopsy was not followed in this case. The diagnosis made only clinical base and blood investigation. In this case report the attempt of drilling of the cortex paved the way for the tumour to extend to all thigh compartments. The limb was beyond salvage at time of presentation. Disarticulation was the final result of the course of the misdiagnosis. References: 1. Paulussen M, Ahrens S, Dunst J, et al: Localized Ewing tumor of bone: Final results of the cooperative Ewing’s Sarcoma Study CESS 86. J Clin Oncol 2001; 19: BPB Tow, MH Tan: Delayed diagnosis of Ewing’s sarcoma of the right humerus initially treated as chronic osteomyelitis: A case report. Journal of Orthopaedic Surgery 2005:13(1): Pritchard DJ, Dahlin DC, Dauphine RT, Taylor WF, Beabout JW: Ewing’s sarcoma: A clinicopathological and statistical analysis of patients surviving five years or longer. J Bone Joint Surg Am 1975;57: Bacci G, Balladelli A, Forni C, et al: Ewing’s sarcoma family tumours: Differences in clinicopathological characteristics at presentation between localised and metastatic tumours. J Bone Joint Surg Br 2007; 89: Dorfman HD, Czerniak B. Ewing’s sarcoma and related entities. In: Dorfman HD, Czerniak B, editors. Bone tumors. Philadelphia: Mosby; 1998:607– Durbin M, Randall RL, James M, Sudilovsky D, Zoger S. Ewing’s sarcoma masquerading as osteomyelitis. Clin Orthop 1998; (357):176– Lyall HA, Constant CR, Wraight EP. Case report: Ewing’s sarcoma in distal tibial metaphysis mimicking osteomyelitis. Clin Radiol 1993; 48:140–2. Department of Orthopaedic Surgery, Khartoum Teaching Hospital.. Case Report Figure x ay shows intramedullary lesion at mid shaft femur with onion skin type of periosteal reaction and multiple drill holes on the cortex. DISCUSSION Ewing’s sarcoma is well known in literature that it has constitutional symptoms like fever and swelling and it mimic chronic osteomyelitis. Ewing’s sarcoma occurs predominantly in the below 20 years of age, and it considers as one of the most aggressive tumours 5. Several cases have been reported misdiagnosis of Ewing’s sarcoma as osteomyelitis. Reasons reported for the misdiagnoses include a low level of suspicion, occurrence at an atypical site, and the lack of or insufficient histologic specimens.6,7. In our case report the primary surgeon rely on his clinical judgment and has a low level of suspicion. The golden rule of biopsy what you culture and send a swab for culture for what you biopsy was not followed in this case. The diagnosis made only on clinical base and blood investigation. In this case report the attempt of drilling of the cortex paved the way for the tumour to extend to all thigh compartments. The limb was beyond salvage at time of presentation. Disarticulation was the final result of the course of the misdiagnosis. Figure 2 MRI showed an enhanced heterogeneous mass at shaft of the femur with soft tissue extension occupying antero- medial and lateral compartment..