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21 Cards in this Set
- Front
- Back
Ulcerative colitis
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A recurrent acute and chronic inflammatory disorder with extensive ulcers of colon and involvement of extracolonic sites
In US, an incidence of nearly 10 per 100,000 with equal sex frequency, most often in 2nd and 3rd decades Familial clustering |
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Ulcerative colitis
Gross Pathology |
Starts in rectum and extends proximally and in continuity
- Can progress to pancolitis over time - There are no skip areas in untreated patients with ulcerative colitis… treatment can make parts look better .: need initial specimen Coalescing ulcers --> progressive mucosal sloughing Pseudopolyps (residual areas of mucosa sitting in an ulcer bed) |
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Ulcerative colitis
Ligh Microscope Pathology Acute |
Mucosal Based
Cryptitis and crypt abscesses that coalesce to undermine mucosa. - Neutrophils in the mucosa - May invade into the crypt (cryptitis) - May form aggregates (abscesses) Marked goblet cell depletion Regeneration |
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Ulcerative colitis
Ligh Microscope Pathology Chronic |
Branched and irregular glands *most important*
- normally all the crypts are coated with connective tissue called the sheath Increased basillar plasma cells in lamina propria *most important* - present at base of mucosa between terminal end of crypt or gland and muscularis mucosa Eosinophils Gap - Space that exists between the base of damage crypt and muscularis mucosa - It is filled with plasma cells and occasionally eosinophils |
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Granulomatous Colitis
Pathology: Gross and LM |
Crohn's Disease of the Colon
- Colon involved in 40% cases of Crohn’s disease; of these ileum in ½ Gross - Segmental (skip areas) - Predominately right sided - Rectal sparing in 50% LM - Minimal mucosal atrophy and regeneration with preserved mucin - Transmural lymphoid aggregates, granulomas, edema, fissures |
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Diverticular Disease
Complications |
Inflammation
Pericolic abscess - If perforation Hemorrhage |
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Diverticular Disease
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Hypertrophy of taeniae coli and circular muscle with flask-shaped sacs of mucosa and submucosa protruding along the side of taeniae
Sigmoid involved in 99% (44% exclusively) Descending colon in 30% Entire colon in 16% |
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Hyperplastic Polyp
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Usually asymptomatic
Common in adult population Present in 30% of all colons, especially the rectum Usually multiple |
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Hyperplastic Polyp
Gross Pathology |
Less than 5 mm
Sessile On mucosal fold crest. |
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Hyperplastic Polyp
Light Microscopy Pathology |
Elongated glands with papillary infolding
Small basal nuclei and abundant mucin No atypia, low nuclear to cytoplasmic ratio, normal polarity Stellate or starfish configuration lumen |
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Juvenile Polyp
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More common in children
This is benign, but can cause rectal bleeding. Single or multiple Rectum is most common site |
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Juvenile Polyp
Gross Pathology |
Pedunculated focally ulcerated, smooth surface round polyp
On sectioning numerous cysts |
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Juvenile Polyp
Light Microscopy Pathology |
Dilated crypts embedded in excess of lamina propria which shows purulent inflammation
- Crypts are dilated with mucus Stomal areas of edema in lamina propria |
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Adenoma-Carcinoma Sequence
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Adenomas are precursors for adenocarcinoma of the large intestine
2/3rds of all adenocarcinomas arise in adenomas Significant features for predicting prognosis (does it harbor cancer): 1. Size - 1% less than 1 cm - 10% 1-2 cm - 50% over 2 cm 2. Histology - Tubular 5% - Tubulovillous 22% - Villous 40% 3. Degree of dysplasia |
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Colonic Adenomas
Light Microscopy Pathology |
• Tubular (75%)
- glands • Villous (10%) - Finger projection • Tubulovillous (15%) • Dysplastic epithelium with reduced mucus • Increased nucleus:cytoplasmic • Hyperchromasia • High mitotic rate • Stratifications |
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Colonic Adenomas
Gross Pathology |
Sharply circumscribed elevations of dysplastic epithelium
Pedunculated or sessile |
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2 Genetic Pathways of Colon Cancer
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Suppressor Pathway
Mutator Pathway |
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Suppressor Pathway
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• Genetic changes in APC, beta-catenin and TCF4
• 80% sporadic colon cancers • FAP • Most often, mutation in APC gene results in abnormal truncated protein • 50% of cases with normal APC gene, mutation in b-cat gene resulting in abnormal protein • In either case, no phosphorylation • b -cat builds in cytoplasm & moves to nucleus • b -cat binds TCF4 • This results in upregulation of #genes. eg bcl-1 & PPAR |
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Mutator Pathway
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• Multiple genetic changes in DNA mismatch repair gene system
• Results in microsatellite instability • 10-20% sporadic cancers • Many cases of CUC cancers • Most often, hypermethylation (& inactivation) of hMHL1 promotor • Increased tendency for more mutations, especially at microsatellites, a few of which are near important genes. |
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Gross Pathology of Colonic carcinoma
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Left
- Circumferential napkin-ring (reducing size) constriction Results in pencil shape bowel movement - Obstruction Right - Exophytic growth (polypoid); anemia |
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Light Microscope Pathology of Colonic carcinoma
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Classic glandular adenocarcinoma
- Lumen containing gland - Contents in lumen: debris = dirty necrosis Colloid variant (Important variant… also known as mucinous… important because worse prognosis) Signet ring variant |