Perineal approach for a gastrointestinal stromal tumor on the anterior wall of the lower rectum

BACKGROUND: Wide margins of resection and regional lymphadenectomy for GIST are not necessary. Several procedures for rectal GIST have been designed according to the location and size of the tumor to preserve the anal function and decrease the morbidity rate. CASE PRESENTATION: We report a 61-year-old-man with rectal bleeding. Proctologic examination revealed a small mass of approximately 2 cm in diameter on the anterior wall of the rectum at a distance of 4 cm from the anal verge. Histological examination of the biopsy sample via the rectum led to a diagnosis of GIST due to immunohistochemical positivity for C117 and CD34. Perineal resection was planned because abdominoperineal resection with sacrificing the sphincter function was excessive for this small tumor, and low anterior resection with the double stapling technique was difficult due to the lower position. A hemispheric incision was made from one mid-ischial tuberosity to the other with an apex of approximately 2 cm above the anus. The fascia band and muscles were successively transected in order to expose the anterior wall of the rectum, and excision of the tumor was performed. The postoperative course was uneventful, and the patient remained free from incontinence and recurrence. CONCLUSIONS: This perineal approach for a GIST on the anterior wall of the rectum is one option for preserving the anal function and decreasing the morbidity rate.