Colon Biopsy
What is Normal? What is Abnormal?
-Naveen
Normal Histology• Flat mucosal surface.
• Columnar surface epithelial cells are intact ;
• Crypt density -7 to 9 /1mm of muscularismucosa
• Goblet cells(1:4) , Paneth cells in right colon
• Parallel crypts – perpendicular to muscularismucosa;
• Cellular infiltrate - lamina propria of normal density, distribution and population ;Plasma cells – Primary lymphoid follicle - eosinophils – occneutrophil
• Sub epithelial zone 3 to 6 microns• No granulomas or giant cells are present• Muscularis mucosae - no splaying, below the
base of crypts• Submucosa – lymphoid follicle- meissner plexus-
ganglion cells
• Intra epithelial lymphocyte- 1 for every 20 cell is normal- not to count the one above the lymphoid aggregate
• Improper fixation- surface epithelial injury with no associated inflammtion
• Enema effect-edema, rbcs, mucin in LP-superficial inflammatory cells -flattening or stripped of surface epithelium
Acute vs chronic colitis
Acute Colitis
– Preservation of crypt architecture
– Within 4 days – mucosal edema, acute cryptits, crypt ulcers and abscesses
– 4 to 9 days – mucus depletion – increased mitotic figures in crypt – cryptitis
– Resolving –hypercellular lamina propria(inflammatory cells)
– Presence of more than 10 neutrophils in more than two crypts in any one biopsy is indicative of active inflammation.
IBD A]Ulcerative colitis
• Severe crypt architectural distortion ;
• Widespread decrease in crypt density ;
• Frankly villous surface;
• Dense diffuse transmucosal increase in cellular infiltrate in the lamina propria ;
• Diffuse basal plasmacytosis;
• Severe mucin depletion ;
• Paneth cell metaplasia distal to the hepatic flexure.
B]Crohn’s Disease
• Epithelioid granuloma ;
• Discontinuous inflammation ;
• Discontinuous crypt distortion ;
• Focal cryptitis.
Non IBD colitisParasitic Colitis
• Amoeba Giardia Cryptosporidium
• eosinophils in lamina propria
Pseudomembranous colitis
• Dilated crypts with inflammatory debris-”volcano”
Graft vs host disease
• Increased number of apoptotic bodies in the surface epithelium
• Crypts -moth eaten
Collagenous colitis
• Pink subepithelial stripe -intact crypt architecture-increase mononuclear cells
• Normal thickness subepithelial - 3 microns
Lymphocytic colitis/ Microscopic colitis
• >20 IEL/100 cells [Normal<5]- Ranitidine
Drug induced colitis
Ischemic colitis
Radiation colitis
• Chronic-Hyalinisaton of lamina propria-fibrotic submucosa, vascular ectasia,fibrinoidnecrosis of vessel wall
• Acute – resemble ischemic colitis
Hirshprung disease
Other non neoplastic conditions
• Diverticulum – mucosa and muscularis mucosa penetrate muscularis propria –smooth muscle hypertrophy
• Endometriosis – endometrial glands, stroma with hemosiderin laden macrophages, fibroblastic response
• Amyloidosis , ingested bone( non viable nuclei)
Polyps
– Non neoplastic
– Inflammatory
– Hamartomatous
» Juvenile –Peutz jegher- cowden-cronkite canda
– Hyperplastic
– Neoplastic
– Adenoma
» Tubular – villous- tubulo villous-sessile serrated
– Carcinoid – stromal- lymphomas- metastatic
Inflammatory polyp
• SRUS –epithelial hyperplasia-mixed inflammation –lamina propria fibromuscular hyperplasia
Hamartomatous polyps
• Juvenile Polyps – spherical lobulated –hamartomatous – irregularly shaped and dilated glands.
• Peutz jeghers polyps – zones of disorganisedmucosa partitioned by smooth muscle
• Cronkhite- canada polyp – similar to juvenile polyp–broad sessile base, expanded edematous lamina propria, cystic glands
Hyperplastic polyp
• Epithelial tufting confined to surface epithelium
Dysplasia vs regenerative hyperplasia
Dysplasia
• Nuclear elongation, Hyperchromatism, Pleomorphism, Stratification, Loss of polarity and no evidence of maturation towards the mucosal surface.
• Large nucleoli-
eosinophilic cytoplasm
reduced goblet cells
Dysplasia
• Low grade – maintained nuclear polarity,
• High grade- loss of polarity, cribriformingpattern,
Adenoma
• Adenoma – high grade dysplasia
• Adenoma with pseudo invasion – rounded glands, lamina propria is dragged in , hemosiderin
• Tubular adenoma Villous adenoma
Tubulo villous adenoma
• Serrated Adenoma– large, high
proliferative index, serrations extending into base,
– dilated architecture of glands from surface to base ,
– mismatch repair gene defect
Adenoma with pseudo invasion
Adenoma with high grade dyspasia
Adeno carcinoma
• Submucosalinvasion or
• If submucosa is not present in the biopsy- angulated glands and single cells, necrosis, in desmoplasticstroma.
Eosinophilic colitis
Dysplasia associated with mass lesionIbd associated dysplasia
Thank You!