Duodenum
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
Normal duodenum
- Three tall villi.
- Few intraepithelial lymphocytes; < 1 lymphocyte / 4 epithelial cells.
- No (pink) subepithelial collagen band.
- Predominant lamina propria cell: plasma cells.
- Lack of plasma cells suggests common variable immunodeficiency (CVID).[1]
- No organisms in lumen.
Basic DDx
- Celiac.
- Intraepithelial lymphocytes - key feature.
- Loss of villi.
- Giarrdia.
- Like celiac... but giarrdia organisms.
- Adenomas.
- Too much blue - similar to colonic adenomas.
- Cancer.
- Too much blue and epithelium in the wrong place.
Duodenal nodules DDX
Duodenal nodule | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Benign (common) | Neoplastic | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Brunner's gland | Heterotopic gastric mucosa | Lymphoid nodule | Adenoma | NET | Paraganglioma | Prolapsed gastric polyp | Metastasis | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Infections of the duodenum[2]
Common:
- Giardia
Rare:
- Cryptosporidia.
- Microsporidia.
- Isospora belli.
- Cyclospora.
- MAI (Mycobacterium avium intracellulare).
- CMV (cytomegalovirus).
- Cryptococcus neoformans.
Celiac sprue
Main article: Celiac sprue
General
- Etiology: autoimmune.
Epidemiology
- Associated with:
- The skin condition dermatitis herpetiformis.[3]
- IgA deficiency - 10-15X more common in celiac disease vs. healthy controls.[4]
- Risk factor for gastrointestinal T cell lymphoma - known as: enteropathy-associated T cell lymphoma (EATL).
Clinical
Treatment:
- Gluten free diet.
- Mnemonic: BROW = barley, rye, oats, wheat.
Serologic testing:
- Anti-transglutaminase antibody.
- Alternative test: anti-endomysial antibody.
- IgA -- assoc. with celiac sprue.
Microscopic
Features:[5]
- Intraepithelial lymphocytes - key feature.
- Should be more pronounced at tips of villi.[6]
- Loss of villi - important feature.
- Normal duodenal biopsy should have 3 good villi.
- Plasma cells - abundant (weak feature).
- Macrophages.
- Mitosis increased (in the crypts).
- +/-Collagen band (pink material in mucosa) - "Collagenous sprue"; must encompass ~25% of mucosa.
Image:
Notes:
- If you see acute inflammatory cells, i.e. neutrophils, consider Giardiasis and other infectious etiologies.
- Biopsy should consist of 2-3 sites. In children it is important to sample the duodenal cap, as it is the only affected site in ~10% of cases.
- Flat lesions without IELs are unlikely to be celiac sprue.
- Mucosa erosions are rare in celiac sprue; should prompt consideration of an alternate diagnosis (infection, medications, Crohn's disease).
Grading
Rarely done - see celiac sprue article.
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.[7]
- Often look like a crescent moon (image of crescent moon) or semicircular[8] -- 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.[9]
Histology
Features:[10]
- 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:
Ampullary tumours
- Ampullary carcinoma - has separate staging.
- Intraductal papillary mucinous tumour (IPMT) - a pancreatic tumour, see pancreas article.
See also
References
- ↑ Agarwal S, Smereka P, Harpaz N, Cunningham-Rundles C, Mayer L (July 2010). "Characterization of immunologic defects in patients with common variable immunodeficiency (CVID) with intestinal disease". Inflamm Bowel Dis. doi:10.1002/ibd.21376. PMID 20629103.
- ↑ Serra S, Jani PA (November 2006). "An approach to duodenal biopsies". J. Clin. Pathol. 59 (11): 1133–50. doi:10.1136/jcp.2005.031260. PMC 1860495. PMID 16679353. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1860495/?tool=pubmed.
- ↑ 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.
- ↑ Biagi F, Luinetti O, Campanella J, et al. (August 2004). "Intraepithelial lymphocytes in the villous tip: do they indicate potential coeliac disease?". J. Clin. Pathol. 57 (8): 835–9. doi:10.1136/jcp.2003.013607. PMC 1770380. PMID 15280404. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1770380/.
- ↑ 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.
External links
Review article(s)
- Serra S, Jani PA (November 2006). "An approach to duodenal biopsies". J. Clin. Pathol. 59 (11): 1133–50. doi:10.1136/jcp.2005.031260. PMC 1860495. PMID 16679353. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1860495/?tool=pubmed.