[A Case of Lower Rectal GIST Treated with Transanal Minimally Invasive Surgery(TAMIS)].

An 82-year-old woman under follow-up for a pancreatic cyst was found to have an approximately 2 cm hypoechoic mass with irregular margins and a heterogeneous internal structure on the dorsal side of the uterus on abdominal ultrasonography. Abdominal CT and MRI was conducted, and rectal GIST was suspected. Due to the patient's strong desire to preserve anal function, transanal minimally invasive surger(y TAMIS)was planned. The procedure was performed in the prone position and the anal was dilated with the Lone Star® RETRACTOR SYSTEM, and the GelPOINT® Path was inserted. Indigo carmine and MucoUp® were injected into the submucosa on both sides of the tumor, followed by mucosal incision. The tumor was partially adhered to the vaginal wall and was resected by shaving off the vaginal wall. The mucosal defect was closed together with the muscular layer using 3-0 V-Loc®, and the surgery was completed. The operative time was 3 h 14 min, with minimal blood loss. The postoperative course was uneventful, and the patient was discharged on postoperative day 10. Imatinib(400 mg/day)was initiated 1 month after discharge but was discontinued after 2 months due to Grade 3 edema. Two years after the surgery, the patient remained recurrence-free.