A CAP Polyposis Occurring in the Full-Thickness Rectal Prolapse

Abstract

Purpose: Cap polyposis is a rare and benign colorectal condition which is characterized histologically by the presence of polyps in the colon and rectum. These polyps are covered by a “cap” of granulation tissue. The pathogenesis of this condition is unknown, but mucosal prolapse secondary to abnormal colonic motility was postulated to be the cause. This disease commonly affects the rectosigmoid colon, and the common symptoms are mucous diarrhea, rectal bleeding, and tenesmus. To our knowledge only a few cases have been reported, and the clinical course remains uncertain. This is a description of a case of cap polyposis occurring in the full-thickness rectal prolapse and which is treated with surgical procedure (Delorme-Thiersch operation). Methods: A 19-year-old man was visited our digestive endoscopy center for evaluation of a rectal polyposis. Three years earlier, he presented with tenesmus associated with bloody and mucous evacuations and urgency. 2.5 years ago, these symptoms were more aggravated with rectal prolapse and he underwent several exams in other hospital. However, he couldn' t got a definitive diagnosis and was treated with 5-ASA suppositories, a budesonide enema, and antibiotics. There was no improvement after these treatments, so he visited our hospital for definitive diagnosis and treatment. Results: Physical examination was unremarkable, but a full-thickness rectal wall prolapse was found when the patient was asked to evacuate with straining. Video proctoscopic findings revealed multiple sessile polypoid lesions with a full-thickness rectal prolapse. Colonoscopy revealed multiple sessile, eroded polypoid lesions up to 8 cm from the anal verge, with a normal intervening mucosa. These polyps were covered with fibrinopurulent exudates. He was diagnosed with cap polyposis occurring in the full-thickness rectal prolapse and treated with surgical procedure (Delorme-Thiersch operation). After the operation, all of his symptoms were disappeared and he does not complaints any problem at defecation. Conclusion: We conclude that rectal prolapse with rectal polyposis may be easily misdiagnosed, if specific details are not noted in the patient's history and on the physical examination. Accurate diagnosis with adequate history taking and examination and adequate therapy may improve the course of a patient with a cap polyposis.Figure