Toxic megacolon is seen in -
Ans. is 'a' i.e.. Chronic non specific ulcerative colitis [Ref: Robbin's 8th/ep. 812 & 7th/ep. 849}Features of E Co Ulcerative colitis involves the rectum and extends proximally.o In severe cases entire colon may be involved - Pancolitis,o It is a disease of continuity, and skip lesions are not found.o In some patients distal ileum may also develop muscosal inflammation - backwash ileitis,o Only mucosa and submucosal layers of colon are involved, deep layers are not involved usually,o Isolated islands of regenerating mucosa buldge upward to create pseudopolyp.o There are superficial mucosal ulcer but they are not serpentine as seen in CD.o Neutrophilic infiltration into crypts leads to formation of crypt abscess.o In sever cases of UC, toxic damage to the muscularis propria and neural plexus lead to complete shutdown of neuromuscular function - colon progressively swells to create "toxic mesocolon ".o There may be epithelial dysplasia with progression to frank carcinoma.DISTINGUISHING FEATURES OF CROHN'S DISEASE AND ULCERATIVE COLITISFEATURECROHN'S DISEASEULCERATIVE COLITISA Macroscopic features 1. DistributionSegmental with skip areasContinuous without skip areas2. LocationCommonly terminal ileum and/or ascending colonCommonly rectum sigmoid colon and extending upwards3. ExtentUsually involves the entire thich- ness of the affected segment of bowel wallUsually superficial, confined to mucosal layers4. UlcersSerpiginous ulcers, that may develop into deep FissuresSuperficial mucosal ulcere without fissures5. PseudopolypsRarely seenCommonly present6. FibrosisCommonRare7. ShorteningDue to fibrosisDue to contraction of muscularisB. Microscopic features L Depth of infiammaionTypically transmuralMuscosal and Submucosal2. Type of infiammaionNon-caseating granulomas and infiltrate of mononuclear cells (lymphocytes, plasma cells and macrophages)Crypt abscess and non-specific acute and chronic inflammatory cells (lymphocytes, plasma cells neutrophils, eosinophils, mast cells)3. MucosaPatchy ulcerationHemorrhagic mucosa with ulceration4. SubmucosaWidened due to edema and lymphoid aggregatesNormal or reduced in width ulceration5. MuscularisInfiltrated by inflammatory cellsUsually spared, except in cases of Toxic Megacolon6, FibrosisPresentUsually absentC Complications 1. Fistula formationInternal and external fistulae in casesExtremely rare2. Malignant changesLess common but presentMay occur in disease of more than 10 years duration (more common )3. Fibrous stricturescommonNever4. Toxic Megacolon--Present5. Named FeaturesHose pipe appearance Cobble-Stone appearanceGarden hose appearance Pseudopolyps
Chronic nonspecific ulcerative colititis
Crohn's disease
Colonic diverticulosis
Hamartomatous polyp
Small and Large Intestines