Rare Case of Appendiceal Gastrointestinal Stromal Tumor: Diagnosis, Surgical Management, and Long-term Outcome

Appendiceal gastrointestinal stromal tumors (GISTs) are exceptionally rare neoplasms.

We report a case of a 68-year-old man who presented with recurrent right lower quadrant abdominal pain. Ultrasonography revealed a 10×4 mm hypoechoic submucosal tumor adjacent to the appendiceal orifice. Contrast-enhanced computed tomography demonstrated a delayed-enhancing appendiceal lesion without regional lymphadenopathy. Laparoscopic appendectomy was performed. Histopathological examination revealed an 8-mm tumor composed of spindle-shaped cells arising from the muscularis propria of the appendix. Immunohistochemical analysis showed positivity for c-kit and CD34, leading to a diagnosis of very low-risk appendiceal GIST.

This case highlights the diagnostic challenges posed by this extremely rare entity and contributes additional long-term outcome data to the limited literature on appendiceal GISTs. Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors of the gastrointestinal tract, most frequently arising in the stomach (approximately 60%) and small intestine (approximately 30%) (1). In contrast, GISTs originating from the appendix are exceedingly rare, accounting for approximately 0.1% of all GISTs (2). Owing to their rarity and small size, appendiceal GISTs are often discovered incidentally and may present diagnostic challenges. Herein, we report a rare case of appendiceal GIST detected preoperatively and successfully treated by laparoscopic appendectomy, with long-term recurrence-free survival.