Large Anal Polyp Disguised as Rectal Prolapse

摘要

Rectal prolapse is a relatively rare condition where the rectal mucosa protrudes out of the anal canal. The diagnosis is made through a physical exam and clinical evaluation, and surgical treatment options can vary. Anal polyps masquerading as rectal prolapse have rarely been described in the literature. A 79-year-old man presented with a four-year history of a bulging, protruding mass from his anus that is exacerbated with defecation and bowel movements. He was initially diagnosed with rectal prolapse and had a proctosigmoidectomy performed robotically. Shortly after the procedure, his symptoms recurred, and he was referred to a different surgeon for reevaluation. A large, prolapsed polyp was visible on the physical exam. A colonoscopy and an anoscopy were performed. The CT abdomen/pelvis revealed a mass within the rectum, and the biopsy showed an adenomatous polyp with high-grade dysplasia. The patient underwent a transanal excision of the rectal polyp, with symptoms permanently resolving. For an accurate diagnosis, it is crucial to conduct a comprehensive assessment of the patient's history, a physical exam, and an unusual clinical course of rectal prolapse. The rarity of large, prolapsed polyps, along with their similar presentation to that of other anorectal conditions, may have contributed to this patient's diagnosis of rectal prolapse and the subsequent proctosigmoidectomy in place of a transanal excision of a polyp. The palpation of a stalk on a physical exam should raise suspicion of a polyp, and further workup, such as a colonoscopy and/or anoscopy, should be conducted to confirm the diagnosis.