Journal of Clinical and Diagnostic Research. 2019 Jan, Vol-13(1): RD06-RD08 6 6 DOI: 10.7860/JCDR/2019/37214.12468 Case Report Orthopaedics Section Ewings Sarcoma of Fourth Metatarsal: A Rare Presentation CHETAN PESHIN 1 , KUNAL DAS 2 , AHMED ABDUL GHAFFAR 3 , SIRAZUL HAQUE MALIK 4 Keywords: Primitive neuroectodermal tumours, Radiotherapy, Surgery ABSTRACT Ewings sarcoma is a primary aggressive neoplasm of bone seen in the second decade of life. This is a case report of a 10-year-old male child who presented with Ewings sarcoma of fourth metatarsal of left side with no distant metastases. Patient was managed by neo-adjuvant therapy followed by wide excision of the tumour followed by adjuvant chemotherapy. He had a very good response and was disease free for up to two years on follow-up. CASE REPORT A 10-year-old male presented with complaints of difficulty in walking for three months and swelling in left foot for four days. There was a history of trauma to the left foot while playing three months back. He had no complaints till that time patient noted a swelling in left foot. On examination, mild swelling and tenderness were present at the dorsum left foot. There was no history of fever or significant weight loss. General physical examination did not show anything significant. The radiograph of left foot was taken and showed an expansile lytic lesion at fourth metatarsal [Table/Fig-1] with cortical breach, aggressive periosteal reaction and soft tissue extension. An MRI scan was done which showed a large soft tissue mass around the involved bone beneath the inferior cortex [Table/Fig-2,3]. The soft tissue mass was present in the fourth metatarsal of left foot with cortical breach and showing heterogeneous enhancement. The full blood count and erythrocyte sedimentation rate were normal (Total Leukocytes Count (TLC), platelet count, total erythrocyte count). Blood workup showed Serum ALP-208 and S. Calcium-9.4 mg/dL. All other parameters were normal. Workup including HRCT chest and bone scan did not reveal any distant metastasis. In view of painful swelling and imaging findings of soft tissue density with a cortical breach, clinical diagnosis of bone sarcoma was considered. Osteosarcoma, Ewings sarcoma and granulomatous infection of bone were considered as differential diagnosis. An open biopsy from the fourth metatarsal was obtained. Histopathological examination showed malignant round cell tumour [Table/Fig-4,5]. Tumour was cellular and arranged in sheets and vague lobules separated by thin vascularised fibrous septae. Cells had round nuclei with coarse chromatin and variable amount of finely vacuolated cytoplasm. Mitotic figures were 1-2/HPF. Necrosis was present. Osteoid deposition, rosette formation or giant cells were not seen. Since the tumour was composed of uniform looking round cells, a diagnosis of malignant round cell neoplasm with differential diagnosis of Ewings sarcoma and non-Hodgkin lymphoma of bone were kept in mind. Immuno-histochemistry, as suggested by the pathologist, was vimentin and CD99 (for Ewings sarcoma) and CD 45 (for lymphoma). [Table/Fig-1]: Preoperative AP X ray of patient showing ill defined lesion in shaft of fourth metatarsal of left foot eroding both the cortices. [Table/Fig-2]: Preoperative MRI (sagittal) demonstrating large soft tissue mass with breach in inferior cortex (arrow) of the lesion. [Table/Fig-3]: Axial cut showing extent of soft tissue involvement (arrow) using t2 weighed post contrast MRI image. (Images from left to right)