Ewing's Sarcoma of the Stomach; Rare Case of Ewing's Sarcoma and Suggestion of New Treatment Strategy
A 35-year-old female who had no special symptoms or past history of cancer was referred for surgical intervention of a protruding mass in her gastric antrum which was incidentally found by Esophagogastroduodenscopy, while she was at a routine medical checkup. Endoscopic examination showed a protruding mass of about 2.5 cm size with a central depression and an erythematous change in the anterior wall of the proximal antrum (). Endoscopic ultrasonogram showed a submucosal tumor noted on the lesion. A laparoscopic gastric wedge resection was done since there was no lymph node enlargement or invasion to other organs. The pathologic gross finding showed a 5.5 cm sized granular tissue with a grape-like appearance (). Histologic examination revealed undifferentiated small round cells containing round and oval nuclei (). Strong membranous CD 99 was noted by immunohistologic study, which is essential for diagnosis of ES. Synaptophysin was also strong by immunohistologic study but chromogranin A, cytokeratin, and desmin were negative (). Fluorescent in situ hybridization for detecting the t(11;22) EWSR1 gene was negative. The patient did not receive any adjuvant chemotherapy or radiotherapy and she remains symptom free and without recurrence for eleven months.