Management of low rectal gastrointestinal stromal tumor with neoadjuvant therapy and transanal excision: a rare case report and review of the literature

Background: Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors of the gastrointestinal tract. However, rectal GISTs represent only 5% of this category. We report a case of a rectal GIST treated with local excision after neoadjuvant therapy. Case presentation: A 41-year-old male patient presented with anal bleeding. Colonoscopy revealed a mass located 5 cm from the anal verge. Histological examination showed a GIST with immunohistochemical positivity for CD117 and CD34. Transanal local excision was performed after neoadjuvant therapy. Conclusion: Neoadjuvant immunotherapy for GISTs with unfavorable localization may facilitate local excision and avoid complications of more demanding operations.