Transvaginal Resection of a Gastrointestinal Stromal Tumor (GIST) of the Rectum.

Gastrointestinal stromal tumors (GISTs) are connective tissue tumors representing a minority of gastrointestinal tumors. A 49-year-old woman was found to have a rectal mass in addition to uterine fibroids during work-up for abnormal uterine bleeding. A peri-rectal mass was again seen during hysterectomy, but definitive resection was deferred. A pelvic MRI suggested a posterior vaginal wall mass. A transvaginal approach was chosen for excision of a solid multi-lobulated mass from the rectovaginal septum space. Frozen section reported uterine leiomyoma, but final pathology confirmed a 10-cm high-risk GIST arising from the rectal muscularis propria, with microscopically positive margins. Patient was started on imatinib therapy. Abdominopelvic resection was offered to decrease the risk of recurrence but was declined. Repeat imaging has shown no obvious distant metastases or residual rectovaginal region mass. The simultaneous and similar presentation of uterine leiomyoma and rectal GIST draws attention to this case.