Diverticulitis

Epidemiology:

• Diverticuli:
• Rare <30y
• 50% of westerners >60y

Common sites:

Gross features:

• tend to occur along taeniae coli
• prominent taeniae coli
• pericolic abscesses, sinus tracts may be present
• colovesical or colovaginal fistula can occur

Histologic features:

• mucosa below muscularis propria
• often thickening of circular layer of MP
• fibrotic thickening of colonic wall (over time)
• may see lymphoid aggregates associated with inflamed diverticula
• surface epithelium next to diverticula may show prolapse-related changes:
• minor inflammation and branching
• thickening of MM
• edema
• watch for coexisting Crohn disease

Immunophenotype:

Marker:

Sensitivity:

Specificity:

Molecular features:

Other features:

References: