A CASE OF A RECTAL GIST DIAGNOSED BY DIRECT VISION BIOPSY WITH AN INCISION OF THE MUCOSA COVERING THE LESION

Abstract

A 63-year-old woman was referred to our hospital for further examination of a rectal submucosal tumor (SMT), which had been discovered by her family doctor. Colonoscopy revealed a solid tumor of 10 mm in diameter covered with normal mucosa at the Rb region of the rectum, indicating it was an SMT such as GIST or leiomyoma. In order to make a final diagnosis of the exact type of SMT, some portion of the SMT was exposed by incising the mucosa covering the lesion, which was followed by a direct vision biopsy using conventional biopsy forceps. The quality and quantity of the biopsy specimen was good enough for pathologists to make a final diagnosis of GIST.
A surgical procedure was subsequently carried out. Primary rectal GIST is considered to have a relatively worse prognosis compared to GIST observed in other area of the gastrointestinal tract. It is also very hard to complete a surgical procedure without affecting defecation function when GIST is advanced. It would be, therefore, very important to diagnose a rectal GIST as early as possible. We therefore propose that direct vision biopsy with an incision of the mucosa covering an SMT can be a very useful technique to make an early diagnosis of rectal GIST.