Diversion colitis

Diversion colitis
Diagnosis in short
Diversion proctitis. H&E stain.
LM	follicular lymphoid hyperplasia key feature (abundant lymphoid nodules, plasma cells), +/-changes of an active colitis (cryptitis, crypt abscesses) - uncommon
LM DDx	inflammatory bowel disease - no stoma, ischemic colitis, infectious colitis
Site	colon, rectum
Clinical history	previous diversion - very important
Prevalence	uncommon
Prognosis	usu. resolves with re-anastomosis
Clin. DDx	other cause of colitis

Diversion colitis is colitis due to a diversion, i.e. a stoma. Diversion proctitis redirects here.

General

• Segment of de-functioned bowel due to surgical diversion, i.e. stoma (ileostomy or colostomy).
• Diagnosis dependent on history - key point.

Gross

Features:

• Ulceration - classic.
• Surgical changes, e.g. fibrotic-appearing thickened wall.
  • May not be apparent.

Microscopic

Features:

• Follicular lymphoid hyperplasia - key feature.
  • Abundant lymphoid nodules.
• Plasma cells and lymphocytes.
• +/-Changes of an active colitis - uncommon:
  • Cryptitis.
  • Crypt abscesses.

Notes:

• May show IBD-like changes.
  • IBD should not be diagnosed on a diverted segment of bowel.

DDx:

• Inflammatory bowel disease - no stoma.
• Ischemic colitis.
• Infectious colitis.
  • Pseudomembranous colitis.

Images

• 

  Diversion proctitis - low mag. (WC/Nephron)

• 

  Diversion proctitis - high mag. (WC/Nephron)

Sign out

SIGMOID COLON, BIOPSIES:
- MILD ACTIVE COLITIS WITH LAMINA PROPRIA FIBROSIS, SEE COMMENT.
- NEGATIVE FOR DYSPLASIA.

COMMENT:
No granulomas are identified.  Follicular lymphoid hyperplasia is not identified;
however, there is no definite submucosa present.

Diverted segments of bowel can have inflammatory bowel disease-like changes.

In the context of a diverted segment of bowel, the findings are compatible with
a diversion colitis.

RECTUM, BIOPSY:
- CHRONIC ACTIVE PROCTITIS WITH FOCAL ULCERATION, CRYPTITIS AND CRYPT ABSCESSES.
- GRANULATION TISSUE.
- NEGATIVE FOR DYSPLASIA.

COMMENT:
No lymphoid hyperplasia is present. A small lymphoid aggregate is present.
Architectural distortion is present.

In the context of a diverted segment of bowel, the findings are compatible with
a diversion colitis.

See also

• Colon.