A Rare Presentation of a Rectal Sessile Serrated Adenoma

Abstract

Colorectal polyps are typically asymptomatic unless advanced in size or malignant. Infrequently, colorectal polyps can present with overt or occult bleeding, abdominal pain or changes in bowel habits. We present a case of a patient with rectal urgency that improved after removal of a sessile serrated adenoma. A 53 year old female with a past medical history of peptic ulcer disease, GERD and a recent small bowel obstruction managed conservatively at an outside hospital presented to our GI outpatient clinic for screening colonoscopy. The patient reported the sensation of anorectal blockage, fullness and urgency. She also reported a change in the caliber and shape of her stool. During the first colonoscopy, our patient was found to have eight 1 to 4 mm polyps in the rectum and recto-sigmoid junction and three diminutive polyps in the rectum, which were biopsied and removed. The pathology showed hyperplastic polyps. However, the preparation was poor so a repeat colonoscopy was done two months later. During the second colonoscopy, a 9 mm sessile polyp was seen in the rectum and ten 1 to 7 mm hyperplastic polyps were seen in the recto-sigmoid colon. The pathology showed a serrated adenoma in the rectum and fragments of normal colonic mucosa in the recto-sigmoid colon. We recommended a repeat screening colonoscopy in 5 years. Anorectal urgency and fullness has been described in multiple gastrointestinal disorders such as IBS, pelvic organ prolapse, solitary rectal ulcer syndrome, and IBD. However, there is little to no literature describing these symptoms in association with colorectal polyps. There are cases of large villous adenomas in the rectum or recto-sigmoid junction causing secretory diarrhea. The severity of disease is typically determined by the size of the lesion and the location in the distal colon, as larger lesions located more distally can cause severe presentations, such as McKittrick-Wheelock syndrome. It is possible that our patient may have been experiencing anorectal urgency and fullness secondary to a sessile serrated adenoma with hypersecretory function. Our patient improved after polyp removal highlighting that colorectal polyps can explain vague, nonspecific gastrointestinal symptoms and polypectomy can be curative.1605_A Figure 1. Rectum: sessile polyp.1605_B Figure 2. Sigmoid colon: hyperplastic polyps.