- Inflammatory bowel disease (IBD) includes ulcerative colitis and Crohn's disease, chronic inflammatory disorders of the gastrointestinal tract. - Ulcerative colitis causes inflammation of the innermost lining of the large intestine and rectum, typically starting in the rectum and left colon. Histologically it is characterized by a lymphoplasmacytic infiltrate with neutrophils and crypt architectural distortion. - Crohn's disease causes transmural, segmental, and patchy inflammation that can involve any part of the GI tract from mouth to anus. It is characterized histologically by discontinuous deep ulcers, non-caseating granulomas, and transmural lympho

1. Histology of IBD
Dr. Heena Wadhwa
Senior Resident
Department of Pathology

2. Normal histology of intestine

4. Inflammatory Bowel Disease
• Group of inflammatory disorders mostly
idiopathic.
• Associated with a number of susceptibility
genes leading to defects in the epithelial
barrier function.
• Activation of the mucosal immune system
driven by the presence of normal luminal flora
(commensal bacteria and their products)

5. Types
1. Ulcerative colitis
2. Crohn’s disease

6. Ulcerative Colitis
• Characteristically a left-sided disease
• Begins in the rectosigmoid area.
• If localized to the rectum (ulcerative proctitis)
• If spreads proximally, sometimes to involve the
entire colon (pancolitis).

7. Gross Features of Ulcerative Colitis

8. Gross Features:Pseudopolyps in UC

10. Histological features

13. Ulcerative Colitis
• Depending on the phase of disease and the
degree of inflammatory activity, UC-related
colitis is categorized as
 chronic inactive,
 chronic active, or
 active (without features of chronicity)
.

15. Ulcerative Colitis
• Chronic colitis (regardless of “activity”) is defined
by the presence of histologic features of
chronicity.
• The degree of activity is graded as
mild if less than 50% of the mucosa shows
evidence of activity,
moderate if more than 50% shows these features,
severe if surface erosion or ulceration is present

16. UC is predominantly a
lymphoplasmacytic inflammatory
process with superimposed
neutrophils, hemorrhage, and
epithelial degeneration. A dense,
homogeneous
lymphoplasmacytic infiltrate
typically expands the lamina
propria

17. The density of plasma cells is
usually greatest in the basal
region of the lamina propria
(termed “basal plasmacytosis”).

18. Crypt architectural distortion,
which is characterized
by irregularly arranged,
branched, dilated, and/or
shortened
crypts.

19. Rupture of crypts because of
inflammation can lead to the
development of aggregates
of histiocytes, foreign body
giant cells, and even well-
developed granulomas, as a
response to extravasated
mucin

22. Backwash Ileitis
• Condition resulting from pan-ulcerative colitis.
• Involves only the distal most portion of ileum, often
less than 10 cm in length.

25. Histologic scoring systems for UC
• Geboes score,
• The Nancy score,
.

26. Geboes score
• The Geboes score has 6 grades:
 0, structural change only;
 1, chronic inflammation;
 2, lamina propria neutrophils/eosinophils;
 3, neutrophils in epithelium;
 4, crypt destruction; and
 5, erosions or ulcers

27. Geboes Score

28. Nancy Score
• The Nancy score defines 5 grades of activity:
1. absence of significant histologic disease,
2. chronic inflammatory infiltrate with no acute
inflammatory infiltrate,
3. mildly active disease,
4. moderately active disease, and
5. severely active disease

29. Nancy Index
(A) Ulceration of colonic mucosa
with inflamed granulation tissue
corresponding to grade 4 of the
Nancy index (HES ×200).
(B) Ulceration of colonic mucosa
with neutrophils in fibrin
corresponding to grade 4 of the
Nancy index (HES ×200).

30. Nancy Index
(C) Presence of multiple clusters of
neutrophils in lamina propria and/or in
epithelium that are easily apparent.
Acute inflammatory cells infiltrate is
moderate to severe, corresponding
to grade 3 of the Nancy index. (HES
×200).
(D) Presence of few or rare
neutrophils in lamina propria or in the
epithelium that are difficult to see.
Acute inflammatory cells infiltrate is
mild, corresponding to grade 2 of the
Nancy index (HES ×200).

31. Nancy Index
(E) Biopsy specimen showing no
acute inflammatory cells infiltrate and
presence of a moderate-to-severe
increase in chronic inflammatory cells
number corresponding to grade 1 of
the Nancy index (HES ×200).
(F) Biopsy specimen showing a mild
increase in chronic inflammatory cell
number. In this case, it defines
a grade 0 of the Nancy index (HES
×200)

32. Crohn’s disease
• It is the chronic recurrent disease characterised
by patchy transmural inflammation involving any
segmentof GIT from mouth to anus.
• Ileocecal region > terminal ileum > diffuse SI >
colon.
• Cigarette smoking is strongly associated.

34. Gross features: Segmental
involvement

36. Gross Features: Apthoid Ulcers

37. Gross features: Cobblestone
Appearance

38. Fat wrapping, or “creeping fat,” is the term used to describe
adherence of mesenteric adipose tissue to the intestinal wall,
in part or in whole.

41. Histological features

43. Slitlike formations with sharp
edges and narrow lumina,
arranged perpendicular to the
mucosa and extending deeply
into the submucosa and even
the muscularis externa

47. One feature that is characteristic
of Crohn’s disease is transmural
lymphoid aggregates, with or
without germinal centers, that
may be present anywhere in the
bowel wall,
from the mucosa to the subserosa.

53. Crohn’s Disease
• Vascular changes observed in mural vessels
include
endothelial injury,
intimal proliferation,
thrombosis, and, rarely,
 granulomatous or fibrinoid vasculitis.

57. Indeterminate Colitis
In a small proportion of IBD cases (1% to 10%, a
definite diagnosis of UC or CD cannot be established
with absolute certainty after evaluation of the patient’s
resection specimen.

60. THANK YOU