An Intrasphincteric Anal Tumor

Abstract

The patient had, for some years, been diagnosed as suffering from an irritable bowel. For a “few months,” she had noticed rectal pain on defecation which had become severe and was aggravated by her bowel frequency. She was not aware of any swelling, but there was a sense of blockage during a bowel action. On examination, there was a smooth, rounded, nontender mass on the left side of the anal canal, extending just above the anorectal junction and bulging into the lumen beneath intact mucosa. It extended into the ischiorectal fossa and was readily palpable in the perianal region. Flexible sigmoidoscopy was normal to 30cm. Transrectal ultrasound (TRUS) revealed a poorly echogenic mass deep to the mucosa within the sphincter muscle. At this examination, fine needle aspiration biopsy was performed. Histologically, this revealed a “smooth muscle tumor” with no evidence of malignancy.