Clinical Case Summary
The term mucosal prolapse polyps (MPP) is used to describe a group of rare colonic lesions that are part of the mucosal prolapse syndrome. They often pose a challenge for gastroenterologists due to their macroscopic similitude to adenomatous polyps and even neoplastic lesions, leading to unnecessary procedures for their removal.
We present the case of a 48-year old woman who underwent colonoscopy for rectal bleeding. Two nodular erythematous lesions of 8’5x4cm, stiff to touch, were identified in the recto-sigmoid. A biopsy was performed twice, showing no histological characterization. Thus, and due to the impossibility of carrying out an endoscopic resection because of their size and uncertain histological nature of the lesions, a trans-anal surgical resection was performed, this time being the histological characterization positive for inflammatory polyp with mucosal prolapse features.
MPP are extremely rare. The biggest case report series to date by Tendler et al. only features 15 cases. Due to the scarcity of published data, MPP’s prevalence and etiology are unclear, though there seems to be an association with constipation and diverticular disease. Their most common clinical presentation is rectal bleeding, although they can remain asymptomatic for years. The endoscopical image is an excrescent, hyperemic lesion, showing the annual tree ring sign, which is relatively new to gastroenterologists. There have been no reported cases where MPP have been a precursor lesion of malignancy.
A high fiber diet should be considered in asymptomatic pacients. In case of recurrent bleeding, an endoscopic or surgical removal seems reasonable depending on the center's experience.
In conclusion, the diagnosis of MPP could be challenging due to to the similarities with other lesions. Gastroenterologists and pathologists should take into account this entity into their differencial diagnosis when facing this kind of lesions to provide efficient healthcare assistance.
References
Tendler DA et al. Prolapsing mucosal polyps: an underrecognized form of colonic polyp--a clinicopathological study of 15 cases. Am J Gastroenterol. 2002 Feb;97(2):370-6. doi: 10.1111/j.1572-0241.2002.05472.x. PMID: 11866275 Libânio D, Meireles C, Afonso LP, Henrique R, Pimentel-Nunes P, Dinis-Ribeiro M. Mucosal Prolapse Polyp Mimicking Rectal Malignancy: A Case Report. GE Port J Gastroenterol. 2016 Feb 18;23(4):214-217. Wong YP, Kabincong C, Jabar MF, Tan GC. Rectal Polyposis in Mucosal Prolapse Syndrome. Diagnostics (Basel). 2022 Apr 12;12(4):966. nEinoder SH, Thomson ACM, Urquhart P, Smart PJ. Prolapsing mucosal fold: largest reported, presenting with major haemorrhage. J Surg Case Rep. 2018 Nov 22;2018(11):rjy312. Prolapsing mucosal polyp: A form of colonic polyp not to be forgotten. Revista de Gastroenterología de México (English Edition), Volume 84, Issue 3, July–September 2019, Pages 407-409. R. Monreal-Robles, J.A. González-González, D.E. Benavides-Salgado, H.J. Maldonado-Garza Huang CC, Frankel WL, Doukides T, Zhou XP, Zhao W, Yearsley MM. Prolapse-related changes are a confounding factor in misdiagnosis of sessile serrated adenomas in the rectum. Hum Pathol. 2013 Apr;44(4):480-6. R. Monreal-Robles, J.A. et al. Prolapsing mucosal polyp: A form of colonic polyp not to be forgotten. Servicio de Gastroenterología y Endoscopia Digestiva, Hospital Universitario «Dr. José E. González» México
