Histopathology - Intestine

Question 1

Answer 1

Acute Appendicitis

 Obstruction of orifice (stool, tumor)progressive increase in intraluminal pressure compresses venous outflow  ischemic injury and stasis of luminal content  bacteria proliferate

 Complications: ulceration, peritonitis

 Edema, neutrophilic infiltration of lumen and tissue

 Mucous membrane is partially missing, indicating ulcer (left side)

 Lymphocytes are normal feature, neutrophils are not

 Secondary lymph follicles do not have germinal centers

 Muscle has abnormal appearance: too many cells, neutrophils present here (contrast with

lymphocytes of pericarditis)

o Transmural inflammation reaching outer layer

 This is appendicitis ulcerophlegmonosa (vs. simplex)

 Fibrin on the surface is inflamed peritoneum

Question 2

Answer 2

Cystic Fibrosis (mucoviscidosis)

(Islet of Langerhans)

 2 different tissues:
o Round structure with lumen is the small intestine with goblet cells and paneth cells.

Nothing should be in the lumen, but here, they are occupied. This is ileus caused by

meconium.
o Pancreas has exocrine glands with islets of Langerhans

 Lots of connective tissue and inflammatory tissue (lymphocytes indicate pancreatitis).

 Eosinophilic viscous secretion in lumen of glands remains there and induces inflammation.

 Glands are dilated and filled with mucin. Some of the cells atrophy; there is fibrosis and scar tissue.

 Digestive enzymes are not sufficient and lead to malabsorption.

 Heterozygosity might be advantageous for survival of cholera and tuberculosis

Question 3

Answer 3

Adenocarcinoma coli

 Top right corner is normal mucosa

 Glands in the tumor are more variable, pseudostratified

 Tumor glands are present in and under the muscularis mucosae

o Muscularis mucosa is broken, indicating that the tumor is advanced, malignant

 Also see tumor glands in the subserous fat tissue

 Pink = stroma

 Dark glands = parenchyma

Question 4

Answer 4

Adenomatous Polyp

 Polyp protrudes into lumen. The polyp is the entire circular structure on the right

 Boarder between polyp and tumor:

o Nuclei normally sit at bottom of goblet cell glands. The tumor is pseudostratified with nuclei apically situated.

 Mucus secretion decreased

 Fewer goblet cells

 Disorganized nuclei

 Morphological variation about cells

 Benign = adenoma; malignant = adenocarcinoma

 Observe muscularis mucosae: if the tumor glands don’t infiltrate the muscularis mucosae,

then it is an adenoma (seen here)

Question 5

Answer 5

Appendix Carcinoid (H&E; Chromagranin A)

 Blood, PMN, lymphocytes

 Normal border

 Normal wall with smooth muscle elements

 Chronic inflammation through wall into peritoneum. In the bottom of the H&E stain, you can

see salt and pepper nuclei in an island of cells

 Neuroendocrine tumor, which used to be described as “carcinoid”

o Neoplasm of APUD (Amine Precursor Uptake Decarboxylase) cells that show differentiation for neuroendocrine elements

 Chromogranin A, synaptophysin, and CD56 are neuroendocrine markers that can be used for staining.

o Proves that this is a neuroendocrine tumor

 Note infiltration (dispersed spreading of brown cells)

 Neuroendocrine Tumors (NET)

o Grade 1
o Grade 2
o Grade 3 = Neuroendocrine Carcinoma

 Appendicitis is also seen. Not infrequently, it is found together with the neoplasm.

Question 6

Answer 6

Celiac Disease, Small Intestine, H&E

 No villi or short villi reduce surface area, leading to malabsorption
 Increased intraepithelial lymphocytes (IEL): 40+ IEL/100 epithelial cells

 T-cell lymphoma may arise

 Hyperplastic crypts of Lieberkühn

Question 7

Answer 7

Ulcerative Colitis, H&E, Large Intestine

 No villi or short villi reduce surface area, leading to malabsorption
 Increased intraepithelial lymphocytes (IEL): 40+ IEL/100 epithelial cells

 T-cell lymphoma may arise

 Hyperplastic crypts of Lieberkühn

 Inflammatory bowel disease

 When uncertain whether the patient has ulcerative colitis or Crohn disease, it is called

‘indeterminate colitis’

 These are endoscopic biopsies

o Only has mucosa. Ulcerative colitis is confined to mucosa.

 Disordered mucosa

 Crypt abscesses have inflammatory neutrophil granulocytes with mixed infiltrate.

o Plasma cells dominate

o Decreased number of goblet cells
 Stroma has mixed infiltrate with plasma cells

Question 8

Answer 8

Crohn Disease, H&E, Large intestine

 Not confined to colon, nor to mucosa

 Transmural – dark blue spots are the lymphoid follicles in lamina propria and adipose tissues

 Ulcer seen on upper left of lumen

 Giant cells in granulomas seen on middle right of lumen. These are common in the follicles