[Retrogastral located gastrointestinal stromal tumor (GIST) as a sonographically detected rare incidental finding]

Gastrointestinal stromal tumors (GIST) represent compared to carcinomas a rare group of neoplasias of the gastro-intestinal tract of unclear dignity. We report the example of a patient suffering from a big retrogastral located gastrointestinal stromal tumor which had been detected as an incidental finding without previous complaints. Because origin and dignity of the process could not definitely be diagnosed, total resection (R0-resection) without systemic lymphadenectomy of the process measuring 11.5 cm x 11 cm x 7 cm was performed. Mitotic activity and tumor-size are regarded as predictive factors of potenzial malignancy of GISTs. In general tumors with low mitotic activity of up to 5 mitoses per 50 high power fields (HPFs) and a diameter smaller than 5 cm are regarded as benign. In the presented case, up to 4 mitoses per 50 HPFs could be detected and thus, in connection with tumor-size, an uncertain biological behaviour of the process has to be expected. Since no generally accepted consensus on the treatment of the GISTs exists, also patients originally suffering from tumors regarded as borderline-malignant should undergo a close-meshed follow-up in regular intervals.