An introduction to gastrointestinal pathology

From Libre Pathology
Revision as of 21:34, 21 January 2012 by Michael (talk | contribs) (→‎See also: rearrange)
Jump to navigation Jump to search

Gastrointestinal pathology is a large part of pathology as radiologists can often describe the extent of disease... but don't get the diagnosis right all the time.

Normal

Layers

Layers of the alimentary canal:[1][2]

  • Mucosa (epithelium, lamina propria, muscularis mucosa).
  • Submuscosa and submucosal plexus (or Meissner's plexus).
  • Muscularis externa (inner longitudinal, myenteric plexus (or Auerbach's plexus) outer circumferential).
  • Adventitia (if retroperitoneal), serosa (if intraperitoneal).

Cell types

  • Goblet cells.
    • Secrete mucin.
  • Enterochromaffin cells, AKA Kulchitsky cells.
    • Subnuclear eosinophilic granules.
      • Serotonin.
  • Paneth cells.
    • Supranuclear eosinophilic granules.

Memory device:

  • Supranuclear granules = paneth cell.

Bowel

Small bowel

  • Villi - should see three good ones in a normal biopsy.
  • Crypts.
  • Paneth cells.
  • Goblet cells.
    • Few in proximal small bowel (duodenum).
    • Abundant in distal small bowel (ileum).

Duodenum

  • Small bowel (as above).
  • Submucosal glands (Brunner's glands).

Large bowel vs. small bowel

  • Small intestine.
    • Villi (key feature).
    • Brunner's glands - duodenum only (key feature).
    • Paneth cells more common.
      • Paneth cells are in the base of the crypts and have eosinophilic granules. They are found (normally) in the small bowel and right colon. They may appear on the left side (i.e. descending colon) in pathologic states, e.g. IBD.
  • Large intestine
    • More goblet cells.
    • More lymphocytes usually.

Luminal gastroenterology

Non-regional

Intestinal polyps

Main article: Intestinal polyps

The bread and butter of gastrointestinal pathology.

Regional

Esophagus

Main article: Esophagus

Largely forgotten organ at SB... but no shortage of these at SMH.

Stomach

Main article: Stomach

H. pylori, cancer and more...

Small bowel

Main article: Small bowel

The part of the GI tract that pathology has mostly forgot. Crohn's disease is dealt with in a separate article.

Duodenum

Main article: Duodenum

Commonly biopsied. Celiac... cancer... giardia?

Colon

Main article: Colon

Colorectal tumours are dealt with in colorectal tumours. Crohn's disease and ulcerative colitis are dealt with in the inflammatory bowel disease article. Includes discussion of the rectum. The anus is a separate article.

Appendix

Main article: Appendix

Acute appendicitis and more...

Accessory organs of the gastrointestinal tract

Gallbladder

Main article: Gallbladder

A growth industry... with the expanding waist lines in the (Western) world.

Liver

Main article: Liver

An organ that pathologists now sometimes forget. There are separate articles for the medical liver diseases, liver neoplasms and liver transplantation pathology.

Pancreas

Main article: Pancreas

An organ that is occasionally afflicted by cancer. It is primarily seen in large centers where they do ERCPs and Whipples.

Pathology (detail articles)

Inflammatory bowel disease

Main article: Inflammatory bowel disease

The bread and butter of gastroenterology and GI pathology.

Gastrointestinal stromal tumour

Main article: Gastrointestinal stromal tumour

The most common GI stromal tumour.

Graft-versus-host disease

Main article: Graft-versus-host disease

An uncommon thing that complicates bone marrow transplants.

Eosinophilic enterocolitis

For the esophageal disease see: Eosinophilic esophagitis.

General

  • Uncommon.
  • Associated with food allergies, esp. in children.[3]

Microscopic

Features:

  • Eosinophilia.
  • Eosinophilic abscesses.

DDx:

  • IBD.
  • Infection.
  • Drug reaction.

Meckel diverticulum

General

  • Most common congenital anomaly of the gastrointestinal tract.[4]

The rule of 2s:

  • 2 feet from the terminal ileum
  • 2% of the population
  • 2% symptomatic.
  • 2 inches long.
  • 2 year old.
  • 2 types of epithelium - gastric and pancreatic.

Gross

  • Antimesenteric attachement.

Image:

Microscopic

Features:

  • Gastric foveolar epithelium:
    • Champagne flute-like columnar epithelium.
  • Pancreatic epithelium:
    • Pancreatic acini.

See also

References

  1. ↑ URL: http://www.lab.anhb.uwa.edu.au/mb140/CorePages/Oral/Oral.htm.
  2. ↑ URL: http://www.lab.anhb.uwa.edu.au/mb140/CorePages/Oral/Images/gitplan.gif.
  3. ↑ Lucendo AJ (September 2010). "Eosinophilic diseases of the gastrointestinal tract". Scand. J. Gastroenterol. 45 (9): 1013–21. doi:10.3109/00365521003690251. PMID 20509820.
  4. ↑ Levy, AD.; Hobbs, CM.. "From the archives of the AFIP. Meckel diverticulum: radiologic features with pathologic Correlation.". Radiographics 24 (2): 565-87. doi:10.1148/rg.242035187. PMID 15026601.

External links

Retrieved from "https://librepathology.org/w/index.php?title=An_introduction_to_gastrointestinal_pathology&oldid=12108"