Transsacral excision with pre-operative imatinib mesylate treatment and approach for gastrointestinal stromal tumors in the rectum: A report of two cases.

Li-Feng Sun,Jun Li,Shao-Jun Yu,Ke-Feng Ding,Shu Zheng,Jing-Hong Xu,Jian-Wei Wang,Jin-Jie He,Yong-Mao Song

doi:10.3892/ol.2014.2406

Abstract

Gastrointestinal stromal tumors (GISTs) are rare in the rectum. Radical surgery, such as an abdominoperineal resection, is necessary for large rectal GISTs, which can result in the loss of function of involved organs. Imatinib mesylate can be used as perioperative therapy and may reduce tumor size, and it is now approved for use in the adjuvant therapy of locally resected anorectal GISTs. The present study describes two cases of large rectal GISTs, for which abdominoperineal resections were initially planned. The two patients received pre-operative imatinib mesylate treatment, and the therapeutic response was assessed by magnetic resonance imaging. Finally, transsacral local resection was successfully performed for these two GISTs. A macroscopically complete resection was achieved, and microscopically, the resection margin was negative. One patient experienced the complication of rectal leakage, which was successfully managed by drainage. No recurrence occurred in the two patients after more than two years. Pre-operative imatinib mesylate therapy with subsequent transsacral local resection for selected rectal GISTs is a feasible treatment modality and can prevent extended surgery.

Highlights

Gastrointestinal stromal tumors (GISTs) are unusual mesenchymal tumors that are commonly found in the stomach (60‐70%), and are found in the small intestine (20‐25%); only 5% of all GISTs originate in the rectum
80‐95% of GISTs typically express cluster of differentiation (CD)117, a tyrosine kinase growth factor receptor (c‐KIT), which can be detected immunohistochemically in order to discriminate GISTs from other mesenchymal gastrointestinal neoplasms [7,8]. c‐KIT serves as the target for drug therapy with imatinib mesylate (IM; Glivec®), a c‐KIT and platelet‐derived growth factor receptor (PDGFR)‐α inhibitor
There are a few studies that have focused on IM adjuvant therapy; these studies have found that following local resection for rectal GISTs, IM is better than, or at least not inferior to, radical surgical low anterior resections (LARs) or abdominoperineal resections (APRs) [9,10,11]

Summary

Introduction

Gastrointestinal stromal tumors (GISTs) are unusual mesenchymal tumors that are commonly found in the stomach (60‐70%), and are found in the small intestine (20‐25%); only 5% of all GISTs originate in the rectum. Less invasive approaches for the local resection of rectal GISTs are often inadequate due to the size of the mass and its exophytic growth. There are a few studies that have focused on IM adjuvant therapy; these studies have found that following local resection for rectal GISTs, IM is better than, or at least not inferior to, radical surgical LAR or APR [9,10,11]. The present study reports two cases of rectal GISTs that were treated by IM adjuvant therapy and subsequent transsacral local resection. Subsequent to 7 months of IM therapy, CT and MRI scans showed no further significant change in tumor size. The patient requested surgery to remove the tumor, and underwent a transsacral local resection (Fig. 2B).

Discussion

Laprascopic ISR

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Findings

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