|
|
| Line 7: |
Line 7: |
|
| |
|
| ==Classification== | | ==Classification== |
| *There is no established system for the classification of toxic megacolon but it may be classified according to etiology into 2 groups:<ref name="pmid1344622">{{cite journal |vauthors=Morón C |title=[The street sales of food and the cholera epidemic in Latin America] |language=Spanish; Castilian |journal=Arch Latinoam Nutr |volume=42 |issue=3 Suppl |pages=36S–40S |year=1992 |pmid=1344622 |doi= |url=}}</ref><ref name="pmid9482465">{{cite journal |vauthors=Sheth SG, LaMont JT |title=Toxic megacolon |journal=Lancet |volume=351 |issue=9101 |pages=509–13 |year=1998 |pmid=9482465 |doi=10.1016/S0140-6736(97)10475-5 |url=}}</ref><ref name="urlToxic Megacolon Complicating a First Course of Crohn’s Disease: About Two Cases (PDF Download Available)">{{cite web |url=https://www.researchgate.net/publication/261883894_Toxic_Megacolon_Complicating_a_First_Course_of_Crohn%27s_Disease_About_Two_Cases |title=Toxic Megacolon Complicating a First Course of Crohn’s Disease: About Two Cases (PDF Download Available) |format= |work= |accessdate=}}</ref><ref name="pmid3981266">{{cite journal |vauthors=Croswell SC, Lei KY |title=Effect of copper deficiency on the apolipoprotein E-rich high density lipoproteins in rats |journal=J. Nutr. |volume=115 |issue=4 |pages=473–82 |year=1985 |pmid=3981266 |doi= |url=}}</ref><ref name="pmid18953191">{{cite journal |vauthors=Earhart MM |title=The identification and treatment of toxic megacolon secondary to pseudomembranous colitis |journal=Dimens Crit Care Nurs |volume=27 |issue=6 |pages=249–54 |year=2008 |pmid=18953191 |doi=10.1097/01.DCC.0000338869.70035.2b |url=}}</ref><ref name="pmid18277885">{{cite journal |vauthors=Berman L, Carling T, Fitzgerald TN, Bell RL, Duffy AJ, Longo WE, Roberts KE |title=Defining surgical therapy for pseudomembranous colitis with toxic megacolon |journal=J. Clin. Gastroenterol. |volume=42 |issue=5 |pages=476–80 |year=2008 |pmid=18277885 |doi=10.1097/MCG.0b013e31804bbe12 |url=}}</ref><ref name="pmid7352781">{{cite journal |vauthors=Grieco MB, Bordan DL, Geiss AC, Beil AR |title=Toxic megacolon complicating Crohn's colitis |journal=Ann. Surg. |volume=191 |issue=1 |pages=75–80 |year=1980 |pmid=7352781 |pmc=1344622 |doi= |url=}}</ref><ref name="pmid11682295">{{cite journal |vauthors=Imbriaco M, Balthazar EJ |title=Toxic megacolon: role of CT in evaluation and detection of complications |journal=Clin Imaging |volume=25 |issue=5 |pages=349–54 |year=2001 |pmid=11682295 |doi= |url=}}</ref><ref name="urlwww.ncbi.nlm.nih.gov">{{cite web |url=https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1552156/pdf/gut00731-0009.pdf |title=www.ncbi.nlm.nih.gov |format= |work= |accessdate=}}</ref><ref name="pmid10823437">{{cite journal |vauthors=Maccioni F, Viscido A, Broglia L, Marrollo M, Masciangelo R, Caprilli R, Rossi P |title=Evaluation of Crohn disease activity with magnetic resonance imaging |journal=Abdom Imaging |volume=25 |issue=3 |pages=219–28 |year=2000 |pmid=10823437 |doi= |url=}}</ref> | | * |
| {|
| |
| ! colspan="2" style="background:#4479BA; color: #FFFFFF;" align="center" + |Etiology of toxic megacolon
| |
| ! style="background:#4479BA; color: #FFFFFF;" align="center" + |Pathological evolution
| |
| ! style="background:#4479BA; color: #FFFFFF;" align="center" + |CT scan findings
| |
| ! style="background:#4479BA; color: #FFFFFF;" align="center" + |MRI findings
| |
| |-
| |
| | rowspan="2" style="background:#DCDCDC;" align="center" + |Toxic megacolon associated with [[inflammatory bowel disease]]
| |
| | style="background:#DCDCDC;" align="center" + |Toxic megacolon associated with [[ulcerative colitis]]
| |
| | style="background:#F5F5F5;" + |
| |
| * Rapid damage involving all layers of the colonic wall
| |
| * Toxins cause a breach in the protective mucosal barrier leading to exposure of muscularis propria
| |
| | style="background:#F5F5F5;" + |
| |
| * Colonic [[dilation]]
| |
| | |
| * Mucosal [[edema]] ([[thumbprint sign]])
| |
| | rowspan="4" style="background:#F5F5F5;" + |
| |
| * Contrast [[MRI]] is superior to CT for visualization of the anal [[sphincter]] complex and the pelvis (especially in case of [[Crohn's disease]]
| |
| * Bowel wall hyperintensity and hyper-enhancement
| |
| * Bright enhancement of mucosa (due to inflammation) and hypoenhancing submucosa (due to edema)
| |
| |-
| |
| | style="background:#DCDCDC;" align="center" + |Toxic megacolon associated with [[Crohn's disease]]
| |
| | style="background:#F5F5F5;" + |
| |
| * Occurs early in the course of [[Crohn's disease]]
| |
| * Develops more commonly in [[pancolitis]] than in segmental disease
| |
| * [[Cytomegalovirus]] infection may be a trigger
| |
| | style="background:#F5F5F5;" + |
| |
| * Colonic [[dilation]]
| |
| * Mucosal [[edema]] ([[thumbprint sign]])
| |
| * Lead-pipe appearance of the [[colon]]
| |
| |-
| |
| | colspan="2" style="background:#DCDCDC;" align="center" + |Toxic megacolon associated with [[Clostridium difficile|''Clostridium difficile'']] [[pseudomembranous colitis]]
| |
| | style="background:#F5F5F5;" + |
| |
| * 0.3-4 percent of cases of [[pseudomembranous colitis]] may develop toxic megacolon
| |
| * Toxic megacolon is thought to develop secondary to [[inflammatory]] changes that penetrate into the muscularis propria leading to neural injury, altered colonic [[motility]] and colonic [[dilation]]
| |
| | style="background:#F5F5F5;" + |
| |
| * Colonic [[dilation]]
| |
| * Mucosal [[edema]] ([[thumbprint sign]])
| |
| * Circumferential colonic wall thickening (accordion sign) consistent with a [[pancolitis]]
| |
| |-
| |
| | colspan="2" style="background:#DCDCDC;" align="center" + |Toxic megacolon associated with [[ischemic colitis]]
| |
| | style="background:#F5F5F5;" + |
| |
| | style="background:#F5F5F5;" + |
| |
| * Colonic [[dilation]]
| |
| * Mucosal [[edema]] ([[thumbprint sign]])
| |
| |}
| |
|
| |
|
| ==References== | | ==References== |