Inflammatory cloacogenic polyp in an adolescent – case report and review of the literature

Summary

Inflammatory cloacogenic polyp is a rare lesion arising in the anal transitional zone. It is usually benign, but rare cases of malignant transformation are known. It is most commonly seen in the adult population from the fourth to the sixth decade of life, but it can be found among children and adolescents as well. The most common clinical symptoms include rectal bleeding and altered bowel habits, although some patients may be asymptomatic. Treatment involves transanal endoscopic microsurgery followed by a bowel regimen with stool softeners. We present the case report of a 14-year-old boy presenting with intermittent rectal bleeding in whom a polypoid lesion was found during digital rectal examination. The patient underwent proctosigmoidoscopy during which the suspicious lesion was removed by transanal endoscopic microsurgery and the histological diagnosis of inflammatory cloacogenic polyp was established. In the postoperative period, the patient was without any further problems. In this case report, we want to raise awareness of this rare diagnosis and emphasize its place in the differential diagnosis of rectal bleeding across all age groups.

Keywords:

children – inflammatory cloacogenic polyp – mucosal prolapse – rectal bleeding – transanal endoscopic microsurgery

INTRODUCTION

Inflammatory cloacogenic polyp (ICP) is a rare, generally benign lesion arising in and near the transitional zone of the anorectal junction [1,2]. A few cases of its malignant transformation have been reported [3–5]. ICP usually affects adults from the fourth to the sixth decade of life [6] and only rarely is it seen in the paediatric population [7,8]. The most common clinical symptom is rectal bleeding [1]. Therapeutically, ICP is managed by transanal endoscopic microsurgery [9].

CASE REPORT

The patient was a 14-year-old boy. He was a normally thriving boy with an adequate psychomotor development. He had been properly vaccinated with no adverse manifestations. Apart from a renal cyst, for which he is followed at the urology outpatient clinic, he had had no physiological morbidities up to this time and no allergic disease. He had not taken any medication for a long time.

The patient had been visiting a surgical outpatient clinic for 6 months due to intermittent rectal bleeding without alteration of bowel habits or other clinical symptoms. During digital rectal examination in the genupectoral position, a palpable polypoid lesion was found at number 6 at a distance of 1 cm from the linea dentata, approximately 1 cm in diameter.

The patient was indicated for rectosigmoideoscopy, where cauliflower-like masses of 2×2 cm, 2×1 cm, 1×1 cm, and 1×1 cm were found, widely attached to the folds of the anal canal, from numbers 2 to 9 (Fig. 1A). The polyps were removed by transanal endoscopic microsurgery (TEM) without subsequent bleeding. The colon was then examined to approximately 60 cm from the anus without pathological findings.

The material was sent for standard histological examination (Fig. 2), which revealed the diagnosis of inflammatory cloacogenic polyp.

The patient was advised to take care to ensure soft stool consistency (i.e. to ensure optimal fluid intake and sufficient fibre intake) and to avoid prolonged straining during defecation.

The patient came for work-up 6 weeks after the procedure. Local findings after removal of the polyps healed without complications (Fig. 1B). Subsequently, esophagogastroduodenoscopy (EGD) and total colonoscopy were also performed as part of the general work-up. Macroscopic findings on EGD did not show any pathology. On colonoscopy, perianal findings were without pathology, the rectum showed a whitish base after polyp removal, and the surrounding area was without signs of inflammation. The entire colon was examined to the caecal base followed by intubation of ileocaecal valve and examination of approximately 30 cm of small intestine. Appearance of the mucosa was normal. Six months after the procedure, the patient is now without clinical symptoms and without signs of recurrence. His stools are regular, passing twice daily, without impaired continence and without any pathological admixture.

DISCUSSION

ICP was first described in 1981 by Lobert and Appelman [1]. The authors chose the adjective “inflammatory” for the histopathological finding of the inflammatory component and “cloacogenic” for the typical localization of ICP – the transitional zone of the anorectal junction, which can also be called the cloacogenic zone.

Etiopathogenetically, chronic mucosal prolapse is a mechanism leading to mucosal ischemia and the development of an inflammatory–regenerative process. The same etiopathogenesis is found also in other nosological entities, such as solitary mucosal ulcer syndrome [10,11], gastric antral vascular ectasia (“watermelon stomach”) [12], inflammatory cap polyposis [13], and polypoid mucosal prolapse [12]. All of these entities tend to be classified under the term “mucosal prolapse syndrome”. This term was first used by du Boulay [14] in 1983. Saul [2] was the first to suggest a possible association between ICP and the solitary rectal ulcer syndrome (SRUS). This idea was also supported by Rodríguez- Leal [15], as ICP and SRUS share certain histopathological features (hypertrophy of the fibromuscular stroma of the lamina propria mucosae, regenerative epithelial changes, superficial epithelial ulceration) and both nosological entities are associated with rectal prolapse. Therefore, ICP probably constitutes only a morphological variant of SRUS. According to Zaman [8], SRUS and ICP are similar concerning their histological features and appearance, but they differ with respect to their location. ICP occurs at the transitional zone of the anal canal, whereas SRUS is usually located in the anterior rectal wall. Another possible etiopathogenetic mechanism has been proposed by Özgenel et al. [16] who suggested that ICP may also arise from mucosal injury associated with internal haemorrhoids, diverticulosis, colorectal cancer, and Crohn’s disease.

ICP is mostly benign in nature, but rare cases of its transformation into anal intraepithelial neoplasia [4], adenocarcinoma [3], or squamous cell carcinoma in situ [5] have been described.

ICP shows a female preponderance and can occur at any age, the highest incidence being between the ages of 30 and 50 [12–17]. It is more common in adults and many cases have been reported [1,4,16–22]. By contrast, only a few cases have been reported in children and adolescents [7,8,20–22]. Munoz [20] was the first to mention ICP in children in 1992. Tab. 1 contains a complete list of published case reports in children.

The most common symptoms of ICP include rectal bleeding (most often mild and intermittent) [2], altered bowel habits [2] (most often presenting with constipation), and painful defecation, especially during prolonged straining [7]. Tenesmus [7] or pruritus ani [8] may also occur. In more advanced stages, a protruding rectal mass may be present [8]. Some patients, however, may be completely asymptomatic [2,19].

Basic assessments include digital rectal examination, colonoscopy, and polyp biopsy. During digital rectal examination, a cauliflower-like mass in the rectum is found; it may even protrude [8] from the rectum at an advanced stage. Upon endoscopic examination, we most often find a sessile polyp [8], usually 1 to 5 cm in diameter [17]. It is typically localized in the anorectal junction, which can make endoscopic visualization difficult, and a retroflexion manoeuvre is often necessary [7]. The polyps may be solitary or multiple [6,16] and may co-exist with a different type of polyp [19]. Endoscopically, ICP may mimic malignant colorectal polyps [23], from which ICP can be distinguished only by histological examination. In ICP, a tubulovillous transformation of the polyp and glandular hyperplasia are conspicuous; the crypts are elongated and irregular. The tips of the polyps are eroded and may be covered with a mucofibrinous cap [6]. The lamina propria shows hypertrophy of the fibromuscular stroma; a variable degree of mixed inflammatory infiltrate may also be present [1]. In some cases, ICP has occurred concomitantly with human papillomavirus (HPV) infection [5]. Therefore, we should consider testing these lesions for HPV [8], given that cases of anal intraepithelial neoplasia have been described in the terrain of ICP [4].

Crohn’s disease, juvenile and adenomatous polyps, Cowden syndrome (i.e. multiple hamartoma syndrome, with multiple hamartomatous lesions affecting, among others, the gastrointestinal tract), and rectal malignancies [17] should be considered in the differential diagnosis. For this reason, it is advisable to perform a complete endoscopic examination of the patient [24].

Therapy may initially be conservative [8], i.e. increasing fibre intake, administering laxatives, and avoiding excessive straining during defecation. However, symptomatic therapy does not lead to the disappearance of the ICP, therefore removal by TEM is recommended. Due to the risk of recurrence, it is necessary to ensure further work-up after ICP removal as well as the adherence to dietary measures (i.e. sufficient fibre intake) in order to avoid constipation and prolonged straining [8].

CONCLUSION

ICP is a rare, and in most cases benign, lesion of the anorectal junction affecting not only adults but also children and adolescents. ICP can be the cause of rectal bleeding accompanied by an alteration in bowel habits. Therefore, it is necessary to consider ICP in the differential diagnosis of rectal bleeding.

List of abbreviations:

EGD    – esophagogastroduodenoscopy

HPV    – human papillomavirus

ICP     – inflammatory cloacogenic polyp

SRUS – solitary rectal ulcer syndrome

TEM   – transanal endoscopic microsurgery

This work was supported by the Ministry of Health of the Czech Republic – conceptual development of research organization (FNBr, 65269705).

Conflict of interests

The authors declare that they do not have a conflict of interest in connection with this paper and that the article has not been published in any other journal, except congress abstracts and clinical guidelines.

doc. MUDr. Petr Jabandžiev, Ph.D.

Department of Paediatrics University Hospital Brno

Cernopolni 212/9 613 00 Brno

e-mail: jabandziev.petr@fnbrno.cz

ORCID:0000-0002-4094-2364