Incidental Finding of a Low-risk Gastrointestinal Stromal Tumor during Bariatric Surgery: A Case Report

Aims: Management of low-grade fusocellular gastrointestinal stromal tumors (GIST) in the context of a clinical case where it is found incidentally during bariatric surgery.

Presentation of Case: Involves the incidental finding of a gastrointestinal stromal tumor (GIST) during bariatric surgery in a 49-year-old female patient. The tumor was located in the jejunum, 120 cm from the ligament of Treitz, with the following histological characteristics: Spindle cell type, low-risk, 1.5 cm in size, with no mitosis, pleomorphism, or necrosis. Positive immunohistochemistry for CD117 (c-KIT), smooth muscle actin, and DOG1. A surgical resection was performed during the gastric bypass procedure. This low- risk GIST was adequately treated with surgical resection. Oncological follow-up is crucial, as the prognosis is favorable for small, low-grade tumors.

Discussion: In this case of an incidental, very low-risk jejunal GIST (<2 cm, <5 mitoses) found during bariatric surgery, there is no established consensus on the optimal surveillance modality and frequency for resected GISTs. However, long-term follow-up is important, as 12.2% of GIST recurrences may occur after five years.

Conclusion: Routine follow-up may not be essential for very low-risk and low-risk GISTs after resection.