Abdominal Wall Extraskeletal Ewing's Sarcoma in an 8-Year-Old Child.

Nonrhabdomyosarcoma soft-tissue sarcomas (NRSTSs) are a heterogeneous group of neoplasms of presumed mesenchymal origin. The precise diagnosis of the type of NRSTS tumor is complex. Among them, Ewing's sarcoma is very rare. We report a case of abdominal wall Ewing's sarcoma in an 8-year-old child. There are very few cases on pediatric abdominal wall Ewing's sarcoma reported. An 8-year-old female child presented with a progressively increasing swelling in the left iliac fossa for 3 months. On evaluation it was found to have a 4 cm × 2.87 cm × 4.1 cm circumscribed, heterogeneous exophytic mass arising from oblique muscles in the left lower abdominal wall with no intraperitoneal extension. On trucut biopsy and karyotyping, it was diagnosed to be an extraskeletal Ewing's sarcoma (EES) of the abdominal wall. Due to the proximity to the pelvic bone and the possible large size, the child was given six cycles of VAEC-IE as neoadjuvant chemotherapy to downsize the tumor. Following chemotherapy, wide excision of the tumor was done requiring partial resection of the external oblique, internal oblique, transverse abdominis, and leaving the transversalis fascia intact. The defect was closed using a polypropylene mesh. Histopathology showed tumor-free margins, with minimal histological tumor response to chemotherapy. Hence, the child underwent radiotherapy (45 Gy in 25 fractions). Follow-up fluorodeoxyglucose-positron emission tomography-computed tomography showed no recurrent lesion. There was no recurrence on 18-month follow-up. Extraskeletal Ewing's sarcoma is a rare tumor arising from the abdominal wall. The evaluation and management are similar to EES. Treatment is multimodal; however, surgery is the mainstay. Wide excision with tumor negative margin has a good outcome.