Histopathological mimicry in mucosal prolapse

Abstract

Mucosal prolapse solitary rectal ulcer syndrome is a condition which has frequently confused both pathologists and surgeons alike. Despite its recognition in the nineteenth century, it continues to be a diagnostic challenge. The significance of correctly diagnosing this condition is that it avoids the morbidity and mortality associated with major surgery or the side-effects of long-term medical treatment. This review considers the histological features of mucosal prolapse and how it may mimic other pathological conditions.

A Rare Cause of Chronic Rectal Bleeding in Children: Solitary Rectal Ulcer (Case Report)

“…Ulcers are usually 1 cm to 1.5 cm and are encircled with hyperemic mucosa. [8,12,[16][17][18][19] Contrary to this general information, three of the four ulcers in our patient were larger than expected and their localization was outside the 5 to 10 cm area above the dentate line, which is the traditional localization.…”

“…[4,5,7,16,17,19,20] In previous reports, the macroscopic appearance of the hyperplastic type could not be distinguished from inflammatory polyp of the rectum or villous adenoma. [4,7,19] The characteristic histopathological findings of SRUS that provide differentiation from other diseases are obliteration with increased fibroblastic activity and presence of collagen deposition in the lamina propria, distortion of crypt architecture, lack of epithelial dysplasia, regenerative changes in crypt epithelium, and muscle fibers derived from muscularis mucosa in the surrounding tissue.…”

“…Multiple ulcers have been reported in 30% of patients. [17] The endoscopic appearance of SRUS can be of three macroscopic types: ulcerative, polypoid and hyperemic. The ulcerative form is the most common in children (60%).…”

“…Some trials suggested digital trauma to the rectal mucosa as a possible factor in developing SRUS. [6,[11][12][13]16,17] Based on these reports, high intrarectal pressure with overactive external sphincter, abnormal contraction of the puborectalis muscles, and anal digitations lead to venous congestion, mucosal ischemia and ulceration. [12,13,[16][17][18][19] However, none of the affirmed hypotheses can exactly explain the pathogenesis.…”

“…[6,[11][12][13]16,17] Based on these reports, high intrarectal pressure with overactive external sphincter, abnormal contraction of the puborectalis muscles, and anal digitations lead to venous congestion, mucosal ischemia and ulceration. [12,13,[16][17][18][19] However, none of the affirmed hypotheses can exactly explain the pathogenesis. [4,9,11] Although SRUS presents generally with rectal bleeding, mucus passage, rectal pain, and tenesmus, additional complaints such as constipation or diarrhea, prolonged straining, altered bowel habits, and rectal prolapsus may be discovered once a detailed history is obtained.…”