Diverticular disease

Diverticular disease, also diverticulosis, is a common disease of the colon. Inflammation of diverticula is known as diverticulitis.

Diverticular disease
Diagnosis in short
Diverticulum. H&E stain.
LM	mucosa/submucosa invaginate into the musuclaris propria
Gross	outpouching - best seen after sectioning
Grossing notes	partial colectomy for diverticular disease
Site	colon - classically sigmoid, other sites
Associated Dx	diverticulitis, peritonitis, diverticular disease-associated colitis
Symptoms	usu. asymptomatic, diverticulitis presents with abdominal pain - classically left lower quadrant
Prevalence	common - especially elderly
Radiology	colonic outpouchings (typically sigmoid colon) +/-pericolic stranding
Clin. DDx	colorectal carcinoma, epiploic appendagitis
Treatment	usually conservative, surgical resection (recurrent or perforating diverticulitis)

General

• Very common.
• Typically seen in elderly patients - 50s and 60s.
• Weakly associated with adenomatous polyps (odd ratio ~ 1.03) - probably due to shared causality (i.e. diet).

Presentations:

• Incidental finding on imaging.
• Abdominal pain.
  • Classically left lower quadrant.
  • +/-Peritoneal signs.
• Blood per rectum.
• Large bowel obstruction.

Complications:

• Diverticulitis - seen in ~25% of individuals with divertiulosis.
• Peformation - peritonitis.
• Diverticular-associated colitis - see below.
• Bowel obstruction - not common, may mimic malignancy.

Diverticular disease-associated colitis

Features:

• Rare.
• Definitions vary somewhat - one is: IBD-like inflammation restricted to areas with diverticular disease.
• Considerable overlap with IBD histologically - no definite histologic findings.
• Rectal biopsy may be used to differentiate from ulcerative colitis.

Gross

• Corrugated - like cardboard.
• Wall thickening (reactive).
• Usually sigmoid colon.
  • May be elsewhere, e.g. appendix.

Images

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  Diverticular disease. (WC/Samir)

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  Drawing of sigmoid diverticula. (WC/Anpol42)

Microscopic

Features:

• Mucosa/submucosa invagination into the musuclaris propria (MP).
  • At the site the blood vessels supplying the mucosa and submucosa penetrate the MP.

Notes:

• Crypt disortion and/or granulomas should not be seen.

DDx:

• Colorectal carcinoma - may cause a stricture, usually obvious on microscopy.
• Inflammatory bowel disease.

Images

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  Diverticular disease. (WC)

www:

• DD (wikispaces.com).

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Sternberg's Diagnostic Surgical Pathology suggests using the term diverticular disease instead of trying to distinguish between diverticulosis and diverticulitis, as diverticulitis clinically may be seen without objective evidence of inflammation.

• This is reasonable, considering that (1) sampling in large specimens may miss the definite active inflammation, and (2) the distinction is academic, as the management is not driven by this detail of the pathologic findings.

Sigmoid Colon, Sigmoidectomy:
- Diverticular disease with surrounding fibrosis and small focus of 
  active mucosal inflammation.
- Four benign lymph nodes.
- NEGATIVE for malignancy.

Block letters

SIGMOID COLON, SIGMOIDECTOMY:
- DIVERTICULAR DISEASE WITHOUT EVIDENCE OF ACTIVE DIVERTICULITIS.
- NEGATIVE FOR MALIGNANCY.

 SIGMOID COLON WITH EEA DONUTS, SIGMOIDECTOMY:
- DIVERTICULAR DISEASE WITHOUT EVIDENCE OF ACTIVE DIVERTICULITIS.
- ONE BENIGN SMALL LYMPH NODE.
- NEGATIVE FOR MALIGNANCY.

Perforated

RECTO-SIGMOID, LARGE BOWEL RESECTION:
- PERFORATED DIVERTICULITIS WITH SEROSITIS AND ABSCESS FORMATION.
- SUBMUCOSAL FIBROSIS.
- ONE LYMPH NODE NEGATIVE FOR MALIGNANCY ( 0 POSITIVE / 1 ).
- NEGATIVE FOR MALIGNANCY.

SIGMOID COLON, RESECTION:
- COLONIC PERFORATION ASSOCIATED WITH FAT NECROSIS, SEROSITIS AND MICROABSCESS
  FORMATION, IN THE SETTING OF DIVERTICULAR DISEASE.
- ONE LYMPH NODE NEGATIVE FOR MALIGNANCY ( 0 POSITIVE / 1 ).
- NEGATIVE FOR DYSPLASIA AND NEGATIVE FOR MALIGNANCY.

See also

• Colon.
• Gastrointestinal pathology.
• Inflammatory bowel disease (IBD).