A rare and unique inflammatory anorectal lesion

A 50-year-old Caucasian woman, without relevant past medical history, was referred to the gastroenterology consultation due to chronic constipation. She had no previous endoscopic evaluation or past surgeries. The digital rectal examination revealed a soft mobile mass at the lower rectum. Pelvic floor dyssynergia was diagnosed on magnetic resonance defecography and, therefore, biofeedback therapy was started. Colonoscopy revealed a light yellowish sessile polyp with 20 mm at the anorectal junction (Figure 1).

Inflammatory Cloacogenic Polyp: A Rare Benign Colorectal Polyp

Inflammatory cloacogenic polyps are a rare kind of benign polyp that is located in the anal transitional zone and rectum. We report the case of a 53-year-old male who underwent a diagnostic colonoscopy for a positive fecal immunochemical test. Two 7 mm polyps were found in the rectum with a pathological diagnosis of inflammatory cloacogenic polyp. The polyp was endoscopically resected. These polyps are associated with chronic inflammatory conditions such as Crohn’s disease and colorectal tumors. Because of malignant transformation potential, inflammatory cloacogenic polyps are endoscopically removed.

Double Early Rectal Cancer Arising from Multiple Inflammatory Cloacogenic Polyps Resected by Endoscopic Submucosal Dissection

A 45-year-old man visited our institution due to the onset of hematochezia. He had a previous episode nine years earlier and colonoscopy at that time revealed multiple polyps, which were consistent with inflammatory cloacogenic polyps (ICPs) on the dentate line. Colonoscopy was performed again and two of the ICPs had grown. Both lesions were pathologically diagnosed as adenocarcinomas based on biopsies. Endoscopic submucosal dissection (ESD) was performed and the two lesions were diagnosed as double well-differentiated adenocarcinomas arising from ICPs. To our knowledge, this is the first reported case of double early rectal cancer in ICPs, which were followed endoscopically and successfully resected with ESD.

Malignant melanoma of the rectum presenting as cloacogenic polyp: a case report

Mucosal malignant melanomas are uncommon. It is rare for a primary mucosal melanoma to occur in the anorectal region. Anorectal polypoid mucosal prolapse however, is a relatively common condition. We report a case of malignant melanoma presenting as mucosal prolapse and inducing changes similar to inflammatory cloacogenic polyp.

Colorectal Serrated Neoplasia: An Institutional 12-Year Review Highlights the Impact of a Screening Programme

Background

As the malignant potential of sessile serrated lesions/polyps (SSL/Ps) and traditional serrated adenomas (TSAs) has been clearly demonstrated, it is important that serrated polyps are identified and correctly classified histologically.

Aim

Our aim was to characterize the clinicopathological features of a series of SSL/Ps & TSAs, to assess the accuracy of the pathological diagnosis, the incidence, and the rate of dysplasia in SSL/Ps & TSAs.

Methods

We identified all colorectal serrated polyps between 01/01/2004 and 31/05/2016, by searching the laboratory information system for all cases assigned a “serrated adenoma” SNOMED code. All available and suitable slides were reviewed by one pathologist, who was blinded to the original diagnosis and the site of the polyp. Subsequently discordant cases, SSL/Ps with dysplasia, and all TSAs were reviewed by a second pathologist.

Results

Over a 149-month period, 759 “serrated adenoma” polyps were identified, with 664 (from 523 patients) available for review. 41.1% were reviewed by both pathologists; 15.1% (100/664) were reclassified, with the majority being changed from SSL/P to hyperplastic polyp (HYP) (66/664; 9.9%). 80.3% of these HYPs were located in the left colon, and the majority exhibited prolapse effect. There were 520 SSL/Ps (92.2%) & 40 TSAs (7.1%). The majority of SSL/Ps were in the right colon (86.7%) and were small (64.5% <1 cm), while most TSAs were in the left colon (85.7%) and were large (73.1%≥1 cm). 6.7% of SSL/Ps exhibited dysplasia, the majority of which were large (66.7%≥1 cm). Following consensus review, 13/520 (2.5%) SSL/Ps were downgraded from SSL/P with dysplasia to SSL/P without dysplasia. Detection of SSL/Ps peaked in the most recent years reviewed (87.5% reported between 2013 and 2016, inclusive), coinciding with the introduction of “BowelScreen” (the Irish FIT-based colorectal cancer screening programme).

Conclusions

Awareness of, and adherence to, diagnostic criteria is essential for accurate classification of colorectal polyps.

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.

Tumours and inflammatory lesions of the anal canal and perianal skin revisited: an update and practical approach

Tumours of the anal and perianal region are relatively rare, and clinically often interpreted as innocuous lesions, leading to frequent delays in diagnosis and adequate treatment. Although squamous cell neoplasia represents the most common entity encountered in this anatomically complex area, many conditions, both neoplastic and inflammatory, may occur. Adding to the challenge of correct diagnosis and patient management, recent years have seen major updates in the terminology of squamous cell neoplasia, created to reflect advances in our understanding of the role of human papilloma virus and unify previous terminologies used for different sites in the anogenital tract. However, squamous cell neoplasia in the anal canal and perianal region may differ in terms of histology, biological behaviour, staging and treatment. The aim of this review is to present an overview of neoplastic and non-neoplastic lesions that may be seen in this area, an update on important developments and terminology, potential pitfalls that may be encountered in routine pathology practice and a practical approach on how to resolve these issues.

Prolapse-related changes are a confounding factor in misdiagnosis of sessile serrated adenomas in the rectum

The differential diagnosis of rectal serrated polyps is challenging due to its unique anatomic location, the evolving concept of serrated polyps over the past several years, and to histologic changes seen in rectal mucosal prolapse. We reclassified 95 rectal polyps diagnosed originally as "sessile serrated adenoma" (SSA), "serrated polyp," or "hyperplastic polyp (HP) with features of SSA" in a 5-year period based on World Health Organization classification criteria for colorectal serrated polyps. BRAF (V600E) mutation assay was performed to explore its value in the differential diagnosis for serrated polyps. Twenty-six originally diagnosed SSAs were reclassified as SSA (15/26, 57.7%), HP with mucosal prolapse (HP-P; 7/26, 26.9%), and HP (4/26, 15.4%). Fifty-two polyps originally diagnosed "HP with features of SSA" were reclassified as HP-P (24/52, 46.2%), HP (10/52, 19.2%), inflammatory-type polyp (5/52, 9.6%), and serrated polyp unclassifiable (13/52, 25.0%). Thirty-one of the 78 originally diagnosed SSA or HP with features of SSA were reclassified as HP-P, which accounted for 32.6% of the rectal polyps in this study. Mucosal prolapse along with chronic inflammation and tissue embedding artifact were the most common features that led to misdiagnosis in rectal serrated polyps. BRAF mutation was identified in 8 of 11 HP, 4 of 4 SSA, and 8 of 11 unclassifiable serrated polyp of the rectum, and was absent in control tissue. Thus, histopathologic changes suggesting prolapsed rectal mucosa should take precedence over BRAF results.