Abstract
OBJECTIVE: In the present study, we aimed to evaluate the clinicopathological features and prognostic factors in extra-gastrointestinal stromal tumor (EGIST) cases, which are observed very rare, by examining the data the cases obtained in a single center. METHODS: Data of 14 EGIST cases who were operated by a general surgeon between January 2007 and May 2020 were obtained and analyzed. RESULTS: The median age was 47.5 (range: 34-87) years. A total of 135 patients were operated for GIST, and 14 (10.4%) of these patients were EGIST. The mean tumor diameter was 16.8±10.5 (range: 2.8-40) cm. The mitotic index was 5/50 high power field and below in seven (50%) cases. Twelve (85.7%) of the patients were in the high-risk group. The overall survival (OS) rate was 80%, and the 5-year survival rate was 88.9%. Mean OS was 78.5±50.7 months, 5-year OS and disease-free survival (DFS) were both 53.3±20.0 months, and overall DFS was 58.0±59.8 months. The mean OS and DFS durations were found to be significantly lower in women than men (p=0.006 for both comparisons). The mean OS was found to be significantly lower in patients over 60 years of age compared to those aged 60 and under (p=0.013). CONCLUSION: In the present study, it has been determined that the rare EGISTs are large in size and that the mitotic index is often low. In addition, it has been observed that the prognosis may be similar to other GISTs, however, may be worse in elderly patients and in women.