Background: Surgery is the principle treatment of resectable non-metastatic rectal GIST. There is a question whether standard oncologic resection or local excision is appropriate in surgery for rectal GIST. The present report is a case of successful transanal excision in a lower rectal GIST patient.
Case Report: A 54-year-old woman presented with passing bright red blood per her rectum for one month. Her physical
examination, colonoscopy with biopsy and CT scan demonstrated a three-centimeter lower rectal GIST with no liver metastasis. The patient underwent an uneventful transanal excision. The operative time was 95 minutes and blood loss was 20 milliliters. The pathology report showed a three centimeter spindle cell type GIST; mitotic count >10/50 high power field with absence of angiolymphatic invasion. The patient received postoperative adjuvant Imatinib Mesylate. No recurrent tumor was detected by either physical examination or CT scan after one year of follow-up and she had neither incontinence nor constipation.
Conclusion: Short-term results both in oncologic clearance and functional outcomes of transanal excision in a small lower rectal GIST (under 3 cm) were acceptable. However, long-term follow-up is still needed.

Keywords: Rectal GIST, Gastrointestinal stromal tumor, GIST, Transanal excision, Local excision