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Megarectum: systematic histopathological evaluation of 35 patients and new common pathways in chronic rectal dilatation

AIMS: Megarectum is well described in the surgical literature but few contemporary pathological studies have been undertaken. There is uncertainty whether ‘idiopathic’ megarectum is a primary neuromuscular disorder or whether chronic dilatation leads to previously reported and unreported pathologica...

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Autores principales: Martin, Joanne E, English, William, Kendall, John V, Sheshappanavar, Vinayata, Peroos, Sara, West, Milly, Cleeve, Stewart, Knowles, Charles
Formato: Online Artículo Texto
Lenguaje:English
Publicado: BMJ Publishing Group 2022
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9510396/
https://www.ncbi.nlm.nih.gov/pubmed/34035078
http://dx.doi.org/10.1136/jclinpath-2021-207413
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author Martin, Joanne E
English, William
Kendall, John V
Sheshappanavar, Vinayata
Peroos, Sara
West, Milly
Cleeve, Stewart
Knowles, Charles
author_facet Martin, Joanne E
English, William
Kendall, John V
Sheshappanavar, Vinayata
Peroos, Sara
West, Milly
Cleeve, Stewart
Knowles, Charles
author_sort Martin, Joanne E
collection PubMed
description AIMS: Megarectum is well described in the surgical literature but few contemporary pathological studies have been undertaken. There is uncertainty whether ‘idiopathic’ megarectum is a primary neuromuscular disorder or whether chronic dilatation leads to previously reported and unreported pathological changes. We sought to answer this question. METHODS: Systematic histopathological evaluation (in accord with international guidance) of 35 consecutive patients undergoing rectal excision surgery for megarectum (primary: n=24) or megarectum following surgical correction of anorectal malformation (secondary: n=11) in a UK university hospital with adult/paediatric surgical and gastrointestinal neuropathology expertise. RESULTS: We confirmed some previously reported observations, notably hypertrophy of the muscularis propria (27 of 35, 77.1% of patients) and extensive fibrosis (30 of 35, 85.7% of patients). We also observed unique and previously unreported features including elastosis (19 of 33, 57.6%) and the presence of polyglucosan bodies (15 of 32, 46.9% of patients). In contrast to previous literature, few patients had any strong evidence of specific forms of visceral neuropathy (5 of 35, including 3 plexus duplications) or myopathy (6 of 35, including 3 muscle duplications). All major pathological findings were common to both primary and secondary forms of the disease, implying that these may be a response to chronic rectal distension rather than of primary aetiology. CONCLUSIONS: In the largest case series reported to date, we challenge the current perception of idiopathic megarectum as a primary neuromuscular disease and propose a cellular pathway model for the features present. The severe morphological changes account for some of the irreversibility of the condition and reinforce the need to prevent ongoing rectal distension when first identified.
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spelling pubmed-95103962022-09-27 Megarectum: systematic histopathological evaluation of 35 patients and new common pathways in chronic rectal dilatation Martin, Joanne E English, William Kendall, John V Sheshappanavar, Vinayata Peroos, Sara West, Milly Cleeve, Stewart Knowles, Charles J Clin Pathol Original Research AIMS: Megarectum is well described in the surgical literature but few contemporary pathological studies have been undertaken. There is uncertainty whether ‘idiopathic’ megarectum is a primary neuromuscular disorder or whether chronic dilatation leads to previously reported and unreported pathological changes. We sought to answer this question. METHODS: Systematic histopathological evaluation (in accord with international guidance) of 35 consecutive patients undergoing rectal excision surgery for megarectum (primary: n=24) or megarectum following surgical correction of anorectal malformation (secondary: n=11) in a UK university hospital with adult/paediatric surgical and gastrointestinal neuropathology expertise. RESULTS: We confirmed some previously reported observations, notably hypertrophy of the muscularis propria (27 of 35, 77.1% of patients) and extensive fibrosis (30 of 35, 85.7% of patients). We also observed unique and previously unreported features including elastosis (19 of 33, 57.6%) and the presence of polyglucosan bodies (15 of 32, 46.9% of patients). In contrast to previous literature, few patients had any strong evidence of specific forms of visceral neuropathy (5 of 35, including 3 plexus duplications) or myopathy (6 of 35, including 3 muscle duplications). All major pathological findings were common to both primary and secondary forms of the disease, implying that these may be a response to chronic rectal distension rather than of primary aetiology. CONCLUSIONS: In the largest case series reported to date, we challenge the current perception of idiopathic megarectum as a primary neuromuscular disease and propose a cellular pathway model for the features present. The severe morphological changes account for some of the irreversibility of the condition and reinforce the need to prevent ongoing rectal distension when first identified. BMJ Publishing Group 2022-10 2021-05-25 /pmc/articles/PMC9510396/ /pubmed/34035078 http://dx.doi.org/10.1136/jclinpath-2021-207413 Text en © Author(s) (or their employer(s)) 2022. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ. https://creativecommons.org/licenses/by-nc/4.0/This is an open access article distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited, appropriate credit is given, any changes made indicated, and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/ (https://creativecommons.org/licenses/by-nc/4.0/) .
spellingShingle Original Research
Martin, Joanne E
English, William
Kendall, John V
Sheshappanavar, Vinayata
Peroos, Sara
West, Milly
Cleeve, Stewart
Knowles, Charles
Megarectum: systematic histopathological evaluation of 35 patients and new common pathways in chronic rectal dilatation
title Megarectum: systematic histopathological evaluation of 35 patients and new common pathways in chronic rectal dilatation
title_full Megarectum: systematic histopathological evaluation of 35 patients and new common pathways in chronic rectal dilatation
title_fullStr Megarectum: systematic histopathological evaluation of 35 patients and new common pathways in chronic rectal dilatation
title_full_unstemmed Megarectum: systematic histopathological evaluation of 35 patients and new common pathways in chronic rectal dilatation
title_short Megarectum: systematic histopathological evaluation of 35 patients and new common pathways in chronic rectal dilatation
title_sort megarectum: systematic histopathological evaluation of 35 patients and new common pathways in chronic rectal dilatation
topic Original Research
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9510396/
https://www.ncbi.nlm.nih.gov/pubmed/34035078
http://dx.doi.org/10.1136/jclinpath-2021-207413
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