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Category Archives: Colon
Attenuated Familial Adenomatous Polyposis
Attenuated Familial Adenomatous Polyposis
AFAP (Attenuated)
Genetics:
- mutations in APC gene 5q chromosome, exon 9 (5’, 3’ ends)
- also mutations to MYH (base excision repair gene)
Gross: flat, plaque-like, less than 100, right colon
Histology
- adenomas, may have adenomatous flat epithelium
Clinical: adenocarcinoma later ~55yrs
Posted in Colon
Tagged adenoma, AFAP, apc gene, Attenuated familial adenomatous polyposis, Colon adenoma, colon adenomas, Colon poylps, colorectal polyps, Familial Adenomatous Polyposis, Familial adenomatous polyposis coli, Many colon polyps, myh gene
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Familial Adenomatous Polyposis
Familial Adenomatous Polyposis
Classic Familial Adenomatous Polyposis
Genetics: Autosomal dominant
- mutations in APC gene 5q chromosome
- APC is a tumour suppressor gene
- non-fnxl APC pr- cannot bind B-catenin
- B-catenin binds to Tcf-Lef proteins
- this activates genes involved in proliferation and inhibition of apoptosis
Extracolonic lesions:
- Fundic gland polyps
- Gardner’s syndrome and extra gastrointestinal lesions (desmoid tumors, epidermoid cyst, osteoma)
- Turcot’s syndrome and medulloblastoma
Diagnosis criteria:
a) 100 plus colorectal polyps
b) germ line mutation in APC gene
c) family history of APC
d) at least one of epidermoid cyst, osteoma or desmoid tumor
Gross: sm, lg adenomas, polyps in colon, distally in colon
Histology: adenomas, may have adenomatous flat epithelium
Clinical: – risk of adenocarcinoma is ~100% by age 50
Posted in Colon
Tagged apc, apc gene, Classic Familial Adenomatous Polyposis, Classic Familial Adenomatous Polyposis Coli, colorectal polyps, Desmoid tumor, epidermoid cyst, Familial Adenomatous Polyposis, Familial adenomatous polyposis coli, family history of APC, FAP, germ line mutation in APC gene, Osteoma
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Sessile Serrated Adenoma
Sessile Serrated Adenoma
- exaggerated serration
- crypt branching
- hypermucinous epithelium
- horizontal extension of the crypt base along the m. mucosa
Posted in Colon
Tagged Serrate adenoma, Sessile serrated adenoma, Sessile serrated polyp
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Mixed Hyperplastic Adenomatous Polyp
Mixed Hyperplastic Adenomatous Polyp
Gross: small, < 1cm
Histology
- surface epithelial nuclear dysplasia (elongation, increased N/C ratio, nucleoli, atypia) and serration of >20%
Dysplasia in Inflammatory Bowel Disease
Dysplasia in Inflammatory Bowel Disease
Clinical: mult biopsy for flat lesions, precedes cancer almost all of the time
Gross appearance: flat, villous or nodular
Histology:
Low grade dysplasia: basal nuclei; mild nuclear (enlargement, crowding and hyperchromasia)
High grade dysplasia: nuclear stratification, nuclei at luminal half, hyperchromasia, pleomorphism; architectural distortion (villous/ nodular)
Indefinite for dysplasia: epithelial changes in a background of active inflammation with regeneration
Posted in Colon
Tagged Cancer risk in inflammatory bowel disease, colitis, colon inflammation, Crohn's disease dysplasia, crohns disease, dysplasia, Dysplasia in Inflammatory Bowel Disease, High grade dysplasia, IBD cancer, IBD dysplaisa, Indefinite for dysplasia, Inflammatory Bowel Disease, Inflammatory bowel disease dysplasia, Inflammatory bowel disease risk of cancer, Low grade dysplasia, Ulcerative Colitis, Ulcerative colitis dysplasia
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Indeterminate Colitis
Indeterminate Colitis
Diagnosis
- cannot distinguish between crohn’s disease and ulcerative colitis
Posted in Colon
Tagged colitis, colon inflammation, crohns disease, Indeterminate colitis, Inflammation of colon, Ulcerative Colitis
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Ulcerative Colitis
Ulcerative Colitis
Location: rectum, progressing proximally, continuous
Symptoms: relapsing, bloody mucoid diarrhea
Extraintestinal symptoms:
Arthritis (migratory polyarthritis)
Sacroilitis
Ankylosing spondylitis
Progressive sclerosing cholangitis
Complications: perforation, toxic megacolon, carcinoma, lymphoma
Treatment: steroids, surgery eventually
Gross:
- ulcers, inflammatory (pseudo) polyps, diffuse continuous disease in colon from rectum proximally (distal is worse)
- can get backwash ileitis
- mural thickening, serositis
Histology
mucosa:
- inflammation and ulcers, n? with crypt abscesses
- ulceration to submucosa
- features of chronicity
wall and serosa:
- submucosal fibrosis
Dysplasia and carcinoma:
- flat mucosa, poorly differentiated or mucinous carcinoma, high stage
Poor prognosis: young, length of bowel invasion, duration of disease
Posted in Colon
Tagged Ankylosing spondylitis, Arthritis, backwash ileitis, bloody diarrhea, colitis, colon inflammation, Extraintestinal symptoms, ileitis, migratory polyarthritis, mucous in stool, mural thickening, Progressive sclerosing cholangitis, Sacroilitis, serositis, Ulcerative Colitis
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Crohns Disease
Crohn’s Disease
Epidemiology:
- associated with HLA DR1/DQw5, white, smokers
Location: throughout GI tract, most common in small bowel and also in colon with rectal sparing
Symptoms: episodic mild diarrhea, pain, blood in stool, mucous in stool
Extraintestinal symptoms:
Arthritis (migratory polyarthritis)
Sacroilitis
Ankylosing spondylitis
Progressive sclerosing cholangitis
Erythema Nodosum
Complications: fibrosing strictures; fistulas to bowel, bladder, vagina and perianal skin; protein losing enteropathy, malabsorption, Vitamin B12 deficiency, bile salt malabsorption with steatorrhea, carcinoma
Treatment: steroids, surgery eventually
Gross appearance:
mucosa: aphthous and linear ulcers, skip lesions (sharp demarcation), cobblestone
wall: edema, thickening, fibrosis,
serosa: sinus tracts, fistulae, creeping fat
Histology:
- superficial or deep ulcers, neutrophils within crypt abscesses
- Paneth cell and pyloric gland metaplasia
- features of chronicity
wall and serosa:
- non-necrotizing granulomatous inflammation – may need serial sections to find
- transmural inflammation with lymphoid aggregates
- fibrosis of submucosa, muscularis propria; hyperplasia of muscularis propria
- serositis
Dysplasia and carcinoma:
Poor prognosis: long duration and severe disease
Posted in Colon
Tagged Ankylosing spondylitis, Arthritis, bile salt malabsorption with steatorrhea, Blood in stool, Bloody stool, carcinoma, Colon discomfort, Colon pain, Colonic pain, Crohn disease, crohns disease, Crohns disease findings, erythema nodosum, Extraintestinal symptoms, IBD, Inflammation of the colon, Inflammatory Bowel Disease, Malabsorption, migratory polyarthritis, Progressive sclerosing cholangitis, protein losing enteropathy, Sacroilitis, Vitamin B12 deficiency
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Inflammatory Bowel Disease Histology
Inflammatory Bowel Disease Histology
- crypt branching
- crypt shortening
- fibrosis
- inflammatory cells
- deep plasma cells
- Paneth cell metaplasia
- crypt distortion and loss
- crypt abscesses
- cryptitis
Posted in Colon
Tagged crohns disease, Inflammatory Bowel Disease, Inflammatory Bowel Disease Histology, Ulcerative Colitis
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Angiodysplasia of the Colon
Angiodysplasia of the Colon
Vascular ectasia of the colon
Clinical presentation: elderly, 20% of lower GI bleeds
- right colon, acquired
Associated with aortic stenosis or von Willebrand disease
Gross appearance: tortuous dilation of submucosal and mucosal blood vessels
Histology
- dilated and thin walled vessels, often with cholesterol emboli
Differential diagnosis
- colonic varices due to portal hypertension
Posted in Colon
Tagged angiodysplasia, Angiodysplasia of the Colon, Vascular ectasia, Vascular ectasia of the colon
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