Mucosal prolapse appearing as a colonic polypoid lesion

Incidentally Discovered Mucosal Prolapse of the Colon During Colorectal Cancer Screening: A Case Report

Colonic mucosal prolapse syndrome is a rare type of non-neoplastic non-inflammatory colorectal polyps that can mimic neoplastic lesions. We present a case of a 65-year-old man with mucosal prolapse syndrome, incidentally, discovered during colorectal cancer screening. The patient was asymptomatic, and his physical exam and laboratory test results were unremarkable. During a colonoscopy, the physician removed three small tubular adenomas and two pedunculated polyps suspicious of neoplasms. Retroflexion revealed small internal hemorrhoids. The histology of the larger polyps revealed mucosal prolapse features, while the smaller polyps displayed features consistent with tubular adenomas. Management involves the removal of associated polyps during colonoscopy, followed by surveillance colonoscopy to detect any recurrent polyps or early signs of colorectal cancer. Accurate diagnosis is crucial to avoid unnecessary interventions and ensure appropriate management.

Rectal mucosal prolapse with an emphasis on endoscopic ultrasound appearance

AIM

The diagnosis of mucosal prolapse syndrome (MPS) continues to be a challenge. Endoscopic ultrasound (EUS) is of clinical value in anorectal diseases. This study seeks to investigate the use of EUS in the diagnosis of MPS.

METHODS

A total of 39 patients diagnosed with MPS between June 2015 to December 2019 were included in this study. Their clinical histories, endoscopic images, EUS images, and pathological data were retrospectively collected, and the EUS images were reviewed to summarize the characteristics of MPS.

RESULTS

In total, 39 MPS patients were enrolled. The main presenting symptoms were bleeding (61.5%) and constipation (53.8%). Gross appearance of the rectal lesions was mainly classified into three types: 51.3% of the lesions were polypoidal/nodular, 33.3% were ulcerative and 15.4% were flat with erythematous mucosa only. A total of 10 patients underwent EUS operation. With regard to the EUS appearance of MPS, four patients with polypoidal/nodular lesions showed thickening of the mucosa on EUS. The diffuse thickening of the mucosa-submucosa layer and disappearance of the architectural structure was observed in four patients with ulcerative lesions. Finally, the thickening of the muscularis propria was observed in two flat lesions. The serosal layers were intact in all the MPS patients. Neither blood flow signals nor regional lymph nodes were observed on EUS.

CONCLUSION

The EUS characteristics for MPS corresponding to different gross appearance can be classified into three types. These findings suggest that EUS is useful in the diagnosis of MPS.

Prolapsing mucosal fold: largest reported, presenting with major haemorrhage

Prolapsing mucosal folds are uncommon benign colonic lesions that when inflamed may macroscopically resemble, and be confused with, an adenomatous or hyperplastic polyp. They are usually small and rarely cause symptoms. We report the case of a 55-year-old female admitted to hospital following six episodes of significant rectal bleeding. A colonoscopy revealed a 45 × 12 × 5 mm³ pedunculated polyp in the sigmoid colon. There was no evidence of haemorrhoids, colitis or diverticulosis. The polyp was resected by electrosurgical snare at 40 cm and a resolution clip was used to prevent postoperative bleeding. Histology of the polyp demonstrated a polypoid prolapsed mucosal fold with a core of fibrovascular submucosal tissue and normal overlying mucosa. In an extensive review of available literature, no polyp of this size has been reported.

Mucosal Prolapse Polyp Mimicking Rectal Malignancy: A Case Report

Mucosal prolapse polyps (MPPs) are rare inflammatory lesions that are part of the mucosal prolapse syndrome. We present the case of a 40-year-old male with history of constipation referred to our institution with suspected rectal malignancy due to hematochezia and a palpable rectal mass. Colonoscopy revealed a 25 mm wide lesion suggestive of subepithelial origin but with marked erythema and erosion in the mucosa. Crypt dilatation and distortion, mixed inflammatory infiltrate and fibrosis were apparent on histological evaluation after bite-on-bite biopsies. Due to the initial suspicion of malignancy, resection was decided after discussion with the patient. However, due to non-elevation partial resection was performed allowing the diagnosis of MPP. Hematochezia ceased after obstipation treatment and endoscopic follow-up showed maintenance of the lesion with the same characteristics except for reduced dimension. MPP may mimic neoplastic lesions and should be considered in the differential diagnosis of rectal masses. History, endoscopy and histological characteristics are all necessary and important in the diagnosis of MPP.