The hypertrophic anal papillae and fibroepithelial polyps are benign lesions consisting of myxoid or collagenous stroma covered by squamous epithelium. They contain mononucleated and multinucleated stromal cells with fibroblastic and myofibroblastic differentiation, and mast cells.3
The occurrence of stromal atypia usually encountered in large size hypertrophic anal papillae/fibroepithelial polyps is considered to be reactive or reparative.4
Awareness of stromal atypia will reduce the likelihood of the misinterpretation of these lesions as malignant tumours. With respect to aetiology, hypertrophic anal papillae and fibroepithelial polyps are considered as a hypertrophic response of the modified anoderm in the region of the anal columns to irritation, injury or infection.3–5
The authors’ interpretation of the physical findings presented here is that a low inter-sphincteric cryptoglandular abscess gave rise to a low type 1 inter-sphincteric fistula-in-ano,2
which was followed by the development and prolapse of a fibroepithelial polyp. The diagnostic accuracy of the type of fistula is supported by the presence of smooth muscle bundles from the internal sphincter in the histology of the specimen (). As its size was larger than the diameter of the fistulous track, it is concluded that the polyp developed up to this size while it was outside the anal canal. However, the development of fibroepithelial polyps in anal fistulae is rarely described. Moreover, the lack of history of abscess formation indicates that the stalk of the polyp could have been functioning as a natural seton, keeping the fistulous track open, facilitating drainage, and prohibiting recurrent abscess formation.2,6
On the other hand, fibroepithelial polyps are commonly associated with chronic anal fissures. The patient’s history was more consistent with a chronic anal fissure. Hence, the fistulous track may represent a healing process from the edges of an anal fissure—that is, a “healed over” anal fissure that resulted in the fistulous track. In either case, the presented physical signs indicate a response to chronic anal pathology.
The hypertrophic anal papillae and fibroepithelial polyps may prolapse, bleed and cause anal discomfort, but are not usually associated with specific symptoms or with chronic idiopathic pruritus ani.7,8
Symptomatic as well as large anal papillae and fibrous anal polyps should be removed and examined histologically. The removal of hypertrophied anal papillae and fibrous anal polyps has also been recommended during the surgical treatment of chronic fissure-in-ano.9
In conclusion, the development and protrusion of a fibroepithelial polyp in an anal fistulous track is described. This is a rare physical sign indicating chronic anal pathology.
- Increased anal sphincter tone, redundant anal skin tags and anal pain render physical examination inconclusive and necessitate examination under anaesthesia.
- Reactive inguinal lymphadenopathy may accompany benign anal pathology.
- Fibroepithelial anal polyps represent a hypertrophic response to irritation, injury or infection that accompanies an anal fistulous track.
- Fibroepithelial anal polyp is a physical sign indicating chronic anal pathology.