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!