33. Path Lab: Inflam and Neoplastic Dz of Bowel

Question 1

Answer 1

Lymphoma of the cecum.

Diffuse dense infiltration of the mucosa by lymphocytes

Question 2

Answer 2

Lymphoma of the cecum

Lympho-epithelial bodies (infiltration of crypt epithelium by lymphocytes). This process leads to crypt destruction.

Question 3

Answer 3

Lymphoma of the cecum.

The lymphocytes are mildly enlarged, have irregular shape and do not show mitoses, consistent with a low-grade lymphoma

Question 4

Answer 4

Crohn’s disease of the terminal ileum

Chronic mucosal inflammation and transmural lymphoid aggregates. Note crypt architectural distortion as a feature of chronicity.

Question 5

Answer 5

Crohn’s

Active inflammation - neutrophils at the top. In GI pathology and especially in IBD, neutrophilic inflammation is called active inflammation, because neutrophils can be seen in a chronic disease.

Question 6

Answer 6

Crohn’s

Knife-like deep fissures reaching muscularis propria is characteristic of Crohn’s disease. Flat-bottom fissures can be seen in severe ulcerative colitis

Question 7

Answer 7

Crohn’s

Epithelioid granulomas are present at the junction of m. propria and subserosal fat (bottom right)

Question 8

Answer 8

Crohn’s

Epithelioid granuloma, high power view (note that it is composed predominantly of histiocytes, few giant cells and admixture of lymphocytes)

Question 9

Answer 9

Acute appendicitis

Destruction of appendicial mucosa (top) and transmural acute inflammation

Question 10

Answer 10

Acute appendicitis

Acute inflammation (neutrophils) in the appendicial wall (note small dark segmented nuclei of neutrophils infiltrating m. propria)

Question 11

Answer 11

Appendicitis

Fibrino-purilent inflammation of the serosa, serositis, corresponding to the clinical diagnosis of peritonitis (bottom).

Question 12

Answer 12

Neuroendocrine (carcinoid) tumor

Neoplastic proliferation in the tip of the appendix

Question 13

Answer 13

Neuroendocrine/Carcinoid Tumor

Nested or confluent growth of epithelioid cells with similar-looking round nuclei and eosinophilic cytoplasm

Question 14

Answer 14

Neuroendocrine/Carcinoid Tumor

“Salt and pepper” chromatin pattern characteristic of well-differentiated neuroendocrine tumors of any organ.

Question 15

Answer 15

Ulcerative Colitis

Chronic active inflammation only in the mucosa. It is always diffuse (without skip areas) in untreated cases. Note crypt architectural distortion as the sign of chronicity and denser than normal inflammatory infiltrate in the lamina propria. Submucosa is completely free from inflammation.

Question 16

Answer 16

Ulcerative Colitis

Cryptitis (neutrophils in the epithelium of the crypts) is a sign of activity of IBD

Question 17

Answer 17

Ulcerative Colitis

Crypt abscesses (neutrophils in the crypt lumina) is a sign of more severe activity of IBD.

Question 18

Answer 18

Pseudomembranous colitis

Abundant inflammatory exudate consisting of mucus, fibrin and neutrophils in the crypts and producing characteristic volcano effect.

Question 19

Answer 19

Pseudomembranous Colitis

High power view showing neutrophils in and around pink mesh of fibrin

Question 20

Answer 20

Tubular adenoma

Hyperplasia and distortion of glandular epithelium

Question 21

Answer 21

Tubular adenoma

Pencil-like, stratified and crowded nuclei of adenomatous dysplasia

Question 22

Answer 22

Tubular adenoma

No invasion of other compartments, such as the lamina propria or the submucosa. Note smooth contour of the crypt bases above the muscularis mucosa without dissecting penetration into deeper compartments.

Question 23

Answer 23

Adenocarcinoma of the colon

Invasive growth of grossly distorted and angulated glands. Note uninvolved mucosa at the upper right corner

Question 24

Answer 24

Adenocarcinoma of the colon

Adenocarcinoma invading m. propria (lower half)

Question 25

Answer 25

Adenocarcinoma of the colon

Nuclear enlargement and pleiomorphism. Chromatin clearing and prominent nucleoli. Single cell apoptosis (large pink cells chromatin bodies)

Question 26

Answer 26

Crohn’s

(Jen notes from lab) Note normal mucosa (normal villi, normal mucsa, submucusa, muscularis) on the lower part of this slide, then in the middle (higher) there is an ulceration and fissures in the mucosa. Note ulceration and presence of inflammation in both submucosa and on the external side of the segment (external inflammation can lead to adhesions with other parts of bowel).

Question 27

Answer 27

Crohn’s

(from Jen’s lab notes)

Close up of fissures in the mucosa, and the ulceration in normal mucosa (top part of horseshoe)

Question 28

Answer 28

Crohn’s

(from Jen’s lab notes)

Close-up of granuloma with multi-nucleated giant cell (pink solid area in center)

Question 29

Answer 29

Lymphoma

(from Jen’s lab notes)

Note all the cells appear to be the same type

Question 30

Answer 30

Appendicitis

(from Jen’s lab notes)

Note serositis (inflammation at external border)

Question 31

Answer 31

Appendicitis

(from Jen’s lab notes)

Zoomed in, lots of inflammatory cells

Question 32

Answer 32

Neuroendocrine Tumor

(from Jen’s lab notes)

Lower right: well-differentiated tumor (dark purple)

Question 33

Answer 33

Neuroendocrine Tumor

(from Jen’s lab notes)

One area becoming nest-like grouping of cells (center)

Question 34

Answer 34

Neuroendocrine Tumor

(from Jen’s lab notes)

Monomorphic cells with salt and pepper nuclei (chromatin is obviously in use)

Question 35

Answer 35

Ulcerative Colitis

(from Jen’s lab notes)

Inflammation of mucosa only, no skips

Question 36

Answer 36

Tubular Adenoma

(from Jen’s lab notes)

Pencil-like nuclei and pseudostratification

Dysplasia but not to the same extent as adenocarcinoma

Question 37

Answer 37

Tubular Adenoma

(from Jen’s lab notes)

Question 38

Answer 38

Adenocarcinoma

(from Jen’s lab notes)

Question 39

Answer 39

Adenocarcinoma

(from Jen’s lab notes)

Invasive growth of grossly distorted glands

Nuclear enlargement and pleiomorphism

Chromatin clearing and prominent nucleoli