Difference between revisions of "Duodenum"
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The '''duodenum''' is the first part of the small bowel. It is accessible by EGD (esophagogastroduodenoscopy) and frequently biopsied. | The '''duodenum''' is the first part of the small bowel. It is accessible by EGD (esophagogastroduodenoscopy) and frequently biopsied. | ||
An introduction to gastrointestinal pathology is in the ''[[gastrointestinal pathology]]'' article. | |||
The clinical history is often: ''r/o celiac'' or ''r/o giardia''. | The clinical history is often: ''r/o celiac'' or ''r/o giardia''. | ||
Revision as of 02:04, 21 September 2010
The duodenum is the first part of the small bowel. It is accessible by EGD (esophagogastroduodenoscopy) and frequently biopsied.
An introduction to gastrointestinal pathology is in the gastrointestinal pathology article.
The clinical history is often: r/o celiac or r/o giardia.
Getting started
- Celiac
- Loss of villi.
- Intraepithelial lymphocytes.
- Giarrdia
- Like celiac... but giarrdia organisms.
- Adenomas
- Too much blue - similar to colonic adenomas.
- Cancer
- Too much blue and epithelium in the wrong place.
Celiac sprue
Etiology
- Autoimmune.
Serology
- Anti-transglutaminase antibody.
- Alternative test: anti-endomysial antibody.
Epidemiology
- Associated with:
- The skin condition dermatitis herpetiformis.[1]
- Tx: dapsone.
- IgA deficiency - 10-15X more common in celiac disease vs. healthy controls.[2]
- Risk factor for gastrointestinal T cell lymphoma - known as: enteropathy-associated T cell lymphoma (EATL).
- The skin condition dermatitis herpetiformis.[1]
Histology
Features:[3]
- Enteritis.
- Intraepithelial lymphocytes - key feature.
- Plasma cells.
- Macrophages.
- Loss of villi - key feature.
- Normal duodenal biopsy should have 3 good villi.
- Mitosis increased (in the crypts).
Notes:
- If you see acute inflammatory cells consider Giardiasis.
Treatment
- Gluten free diet.
- Mnemonic: BROW = barley, rye, oats, wheat.
DDx
- Giardiasis.
- Have giarrdia organisms.
- Always consider Giardiasis and especially on exams.
- Whipple's disease (very rare).
- Abundant macrophages should make one suspicious.
Giardiasis
Etiology
- Flagellate protozoan Giardia lamblia.
Histology
- Loss of villi.
- Intraepithelial lymphocytes.
- +Other inflammatory cells, especially PMNs, close to the luminal surface.
- Flagellate protozoa -- diagnostic feature.
- Organisms often at site of bad inflammation.
- Pale/translucent on H&E.
- Size: 12-15 micrometers (long axis) x 6-10 micrometers (short axis) -- if seen completely.[4]
- Often look like a crescent moon (image of crescent moon) or semicircular[5] -- as the long axis of the organism is rarely in the plane of the (histologic) section.
Notes:
- Giardiasis can look (histologically) a lot like celiac disease.
Images:
Treatment
- Antibiotics, e.g. metronidazole (Flagyl).
Whipple's disease
Epidemiology
- Very rare.
- Classically middle aged men.
Clinical
- Malabsorption (diarrhea), arthritis + others.
- Symptoms are non-specific.
Etiology
- Infection - caused by Tropheryma whipplei.[6]
Histology
Features:[7]
- Infectious microorganism typically found in macrophages.
- Macrophages usually abundant - key feature that should raise Dx in DDx.
- Organisms periodic acid-Schiff (PAS) positive.
Treatment
- Antibiotics - for months and months.
Micrograph: Whipple's disease - wikipedia.org.
Tumours
Lymphoma
Main article: Lymphoma
- Non-Hodgkin's lymphoma.
- Enteropathy-associated T-cell lymphoma (EATL) - due to celiac sprue.
- Image: EATL - low mag. (WC).
- MALT lymphoma - common GI tract lymphoma.
- Mantle cell lymphoma.
- Diffuse large B cell lymphoma.
- Enteropathy-associated T-cell lymphoma (EATL) - due to celiac sprue.
Note:
- Hodgkin's lymphoma does not arise in the GI tract.
Adenocarcinoma
- Similar to large bowel adenocarcinomas (see colorectal tumours article).
- Duodenum - most common site in small bowel.
Risk factors:
Neuroendocrine tumours
General
Microscopic
Features:
- Nests of cells.
- Stippled chromatin - AKA: salt-and-pepper chromatin, coarse chromatin.
- Classically subepithelial/mural.
Images:
- Neuroendocrine tumour - low mag. (WC).
- Neuroendocrine tumour - intermed. mag. (WC).
- Neuroendocrine tumour - high mag. (WC).
Ampullary tumours
- Ampullary carcinoma - has separate staging.
- Intraductal papillary mucinous tumour (IPMT) - a pancreatic tumour, see pancreas article.
See also
References
- ↑ TN 2007 D22
- ↑ Kumar, V.; Jarzabek-Chorzelska, M.; Sulej, J.; Karnewska, K.; Farrell, T.; Jablonska, S. (Nov 2002). "Celiac disease and immunoglobulin a deficiency: how effective are the serological methods of diagnosis?". Clin Diagn Lab Immunol 9 (6): 1295-300. PMID 12414763.
- ↑ Cotran, Ramzi S.; Kumar, Vinay; Fausto, Nelson; Nelso Fausto; Robbins, Stanley L.; Abbas, Abul K. (2005). Robbins and Cotran pathologic basis of disease (7th ed.). St. Louis, Mo: Elsevier Saunders. pp. 843. ISBN 0-7216-0187-1.
- ↑ http://www.water-research.net/Giardia.htm
- ↑ http://en.wikipedia.org/wiki/Semicircle
- ↑ Liang Z, La Scola B, Raoult D (January 2002). "Monoclonal antibodies to immunodominant epitope of Tropheryma whipplei". Clin. Diagn. Lab. Immunol. 9 (1): 156?9. PMC 119894. PMID 11777846. http://cvi.asm.org/cgi/pmidlookup?view=long&pmid=11777846.
- ↑ Bai J, Mazure R, Vazquez H, Niveloni S, Smecuol E, Pedreira S, Mauriño E (2004). "Whipple's disease". Clin Gastroenterol Hepatol 2 (10): 849?60. doi:10.1016/S1542-3565(04)00387-8. PMID 15476147.
- ↑ Chetty, R. (Apr 2008). "Requiem for the term 'carcinoid tumour' in the gastrointestinal tract?". Can J Gastroenterol 22 (4): 357-8. PMID 18414708.
- ↑ Klöppel, G.; Perren, A.; Heitz, PU. (Apr 2004). "The gastroenteropancreatic neuroendocrine cell system and its tumors: the WHO classification.". Ann N Y Acad Sci 1014: 13-27. PMID 15153416.
- ↑ Klöppel G (July 2003). "[Neuroendocrine tumors of the gastrointestinal tract]" (in German). Pathologe 24 (4): 287–96. doi:10.1007/s00292-003-0636-7. PMID 14513276.