Duodenum

Schematic of the duodenum. (WC/Luke Guthmann)

The duodenum is the first part of the small bowel and receives food from the stomach. 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

• Abbreviated ND.

General

• Very common.

Microscopic

• 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).
• No organisms in lumen.

DDx:

• Intestinal metaplasia of the stomach - foveolar epithelium + other histologic components of the stomach.
• Chronic duodenitis - foveolar epithelium, Brunner's gland hyperplasia.

Sign out

Duodenum, Biopsy:
- Small bowel mucosa and Brunner's glands within normal limits.

Duodenum, Biopsy:
- Small bowel mucosa within normal limits.

Duodenum, Biopsy:
- Small bowel mucosa within normal limits.
- NEGATIVE for findings suggestive of celiac disease.

Small Bowel (Duodenum), Biopsy:
- Small bowel mucosa within normal limits.
- NEGATIVE for findings suggestive of celiac disease.

Block letters

DUODENUM, BIOPSY: 
- SMALL BOWEL MUCOSA AND BRUNNER'S GLANDS WITHIN NORMAL LIMITS.

DUODENUM, BIOPSY: 
- SMALL BOWEL MUCOSA WITHIN NORMAL LIMITS.

DUODENUM, BIOPSY: 
- SMALL BOWEL MUCOSA WITHIN NORMAL LIMITS.
- NEGATIVE FOR FINDINGS SUGGESTIVE OF CELIAC DISEASE.

SMALL BOWEL (DUODENUM), BIOPSY: 
- SMALL BOWEL MUCOSA WITHIN NORMAL LIMITS.
- NEGATIVE FOR FINDINGS SUGGESTIVE OF CELIAC DISEASE.

Basic DDx

• Celiac sprue.
  • Intraepithelial lymphocytes - key feature.
  • Loss of villi.
• Giardia.
  • Like celiac... but giardia organisms.
• Adenomas.
  • Too much blue - similar to colonic adenomas.
• Cancer.
  • Too much blue and epithelium in the wrong place.

More

• H. pylori only in areas of gastric metaplasia.

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

Common:

• Giardia.

Rare:

• Cryptosporidia.
• Microsporidia.
• Isospora belli.
• Cyclospora.
• MAC (Mycobacterium avium complex).
• CMV (cytomegalovirus).
• Cryptococcus neoformans.

Common stuffs

Gastric heterotopia of the duodenum

• AKA heterotopic gastric mucosa.

Main article: Gastric heterotopia of the duodenum

Celiac sprue

Main article: Celiac sprue

General

• Etiology: autoimmune.

Epidemiology

• Associated with:
  • The skin condition dermatitis herpetiformis.
  • IgA deficiency - 10-15X more common in celiac disease vs. healthy controls.
  • 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:

• Intraepithelial lymphocytes (IELs) - key feature.
  • Should be more pronounced at tips of villi.
  • Criteria for number varies:
    • > 40 IELs / 100 enterocytes (epithelial cells).
    • > 25 IELs / 100 enterocytes (epithelial cells).
• 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:

• Celiac sprue (WC).

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

Main article: Giardiasis

Acute duodenitis

• Abbreviated AD.

Main article: Acute duodenitis

Chronic duodenitis

General

• This is not very well defined as plasma cells are present in a normal duodenum.

Gross

• Duodenal erythema.

Microscopic

Features:

• "Abundant" lamina propria plasma cells.
• Villous blunting.
• Brunner's gland hyperplasia.

DDx:

• Normal duodenum.

Sign out

DUODENUM, BIOPSY:
- MODERATE NON-SPECIFIC CHRONIC DUODENTIS (SMALL BOWEL MUCOSA WITH VILLOUS
  BLUNTING, PROMINENT BRUNNER'S GLANDS, ABUNDANT LAMINA PROPRIA PLASMA CELLS
  AND OCCASIONAL INTRAEPITHELIAL LYMPHOCYTES, WITHOUT FOVEOLAR METAPLASIA).
- NEGATIVE FOR DYSPLASIA.

Peptic duodenitis

General

• A somewhat controversial type of chronic duodenitis.
• Considered to be a consequence of peptic ulcer disease (Helicobacter gastritis).
• One of the key components of the diagnosis is foveolar metaplasia and it is disputed that this is really due to Helicobacter.
  • Genta et al. consider gastric foveolar metaplasia a congenital lesion.

Microscopic

Features:

• Gastric foveolar metaplasia - key feature.
• Brunner's gland hyperplasia.
• +/-Inflammation - neutrophils.^{[citation needed]}
• Ulceration.^{[citation needed]}

DDx:

• Chronic duodenitis not otherwise specified - no foveolar metaplasia, abundant plasma cells.
• Acute duodenitis.
• Brunner's gland hyperplasia.
• Gastric heterotopia of the duodenum.

Images

• 

  Duodenum with foveolar metaplasia - low mag. (WC/Nephron)

• 

  Duodenum with foveolar metaplasia - intermed. mag. (WC/Nephron)

• 

  Duodenum with foveolar metaplasia - very high mag. (WC/Nephron)

Stains

Foveolar metaplasia:

• PAS stain +ve.
• Mucicarmine stain +ve.

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Foveolar metaplasia only

DUODENUM, BIOPSY:
- SMALL BOWEL MUCOSA WITH FOCAL GASTRIC FOVEOLAR METAPLASIA.
- BRUNNER'S GLANDS NOT IDENTIFIED.
- VILLI AND INTRAEPITHELIAL LYMPHOCYTES WITHIN NORMAL LIMITS (NEGATIVE FOR CELIAC DISEASE).
- NEGATIVE FOR ACUTE DUODENITIS.
- NEGATIVE FOR DYSPLASIA.

DUODENUM, BIOPSY:
- SMALL BOWEL MUCOSA WITH FOCAL GASTRIC FOVEOLAR METAPLASIA.
- BRUNNER'S GLANDS NOT IDENTIFIED.
- NEGATIVE FOR ACUTE DUODENITIS.
- NEGATIVE FOR DYSPLASIA.

Chronic duodenitis

Duodenum, Biopsy:
- Small bowel mucosa with Brunner’s gland in the lamina propria and gastric foveolar metaplasia, consistent with chronic duodenitis.
- NEGATIVE for acute duodenitis.
- NEGATIVE for dysplasia and NEGATIVE for malignancy.

DUODENUM, BIOPSY:
- SMALL BOWEL MUCOSA WITH BRUNNER'S GLAND IN THE LAMINA PROPRIA AND
  GASTRIC FOVEOLAR METAPLASIA -- CONSISTENT WITH CHRONIC DUODENITIS.
- NEGATIVE FOR ACUTE DUODENITIS.
- NEGATIVE FOR MALIGNANCY.

 DUODENUM, BIOPSY:
- SMALL BOWEL MUCOSA WITH PROMINENT BRUNNER'S GLANDS AND FOCAL GASTRIC
  FOVEOLAR METAPLASIA.
- NEGATIVE FOR ACUTE INFLAMMATION.
- NEGATIVE FOR DYSPLASIA.

Micro

The sections show small bowel mucosa and a small amount of submucosa. Brunner's glands are abundant and found focally in the lamina propria. Gastric foveolar-type epithelium is identified. Intraepithelial neutrophils are not identified.

The epithelium matures appropriately. There is no increase in intraepithelial lymphocytes.

Brunner's gland hyperplasia

Brunner's gland hamartoma redirects here.

• Abbreviated BGH.
• AKA Brunneroma.

General

• Benign.
• Usually asymptomatic.

Note:

• The AFIP uses the term Brunner's gland hamartoma for lesions > 5 mm.
  • Multiple lesions less than 5 mm are hyperplasia.

Gross

• Nodularity of the duodenum.

Microscopic

Features:

• Prominent Brunner's gland.
  • Tubular structures - formed by cells abundant cytoplasm that is clear with eosinophilic "cobwebs" and a round, small basal nucleus without a nucleolus.
  • Brunner's glands close to the surface epithelium - key feature.
• +/-Pancreatic acini and ducts.

DDx:

• Foveolar metaplasia (isolated) - see peptic duodenitis.
• Peptic duodenitis.

Image:

• BGH (nih.gov).
• BGH (ajronline.org).

Sign out

DUODENUM, BIOPSY:
- CONSISTENT WITH BRUNNER'S GLAND HYPERPLASIA.
- SMALL BOWEL MUCOSA WITHOUT SIGNIFICANT PATHOLOGY.

 DUODENUM, BIOPSY:
- SMALL BOWEL MUCOSA WITHOUT SIGNIFICANT PATHOLOGY.
- PROMINENT BRUNNER'S GLANDS WITH EXTENSION INTO THE LAMINA PROPRIA.

Superficial Brunner's glands

DUODENUM, BIOPSY:
- SMALL BOWEL MUCOSA WITH BRUNNER'S GLANDS THAT ARE FOCALLY SUPERFICIAL.
- NO FINDINGS SUGGESTIVE OF CELIAC DISEASE.
- NEGATIVE FOR ACTIVE INFLAMMATION.
- NEGATIVE FOR DYSPLASIA.

Micro

The sections show small bowel mucosa and a small amount of submucosa. Brunner's glands are abundant and found focally in the lamina propria.

The epithelium matures appropriately. There is no increase in intraepithelial lymphocytes. No foveolar metaplasia of the epithelium is identified.

Weird stuff

Disaccharidases deficiency

General

• Common among asians.
• Includes: lactase, sucrase, and maltase.
  • Lactase changes seen with mild histomorphologic changes.
  • Maltase and sucrase only affected in moderate and severe lesions.

Microscopic

Features:

• Decreased villous-crypt ratio (mild to severe).
• +/-Inflammation (only in moderate and severe).

DDx:

• Celiac disease.

Notes:

• May have normal histomorphology.

Whipple disease

Main article: Whipple's disease

Microvillous inclusion disease

Main article: Microvillous inclusion disease

This rare disease presents very shortly after birth.

Tufting enteropathy

• AKA intestinal epithelial dysplasia.

General

• Genetic disease - related to abnormal enterocytes (development and/or differentiation).
  • Gene implicated: EPCAM.

Microscopic

Features:

• Villous atrophy
• Mononuclear cell infiltration of the lamina propria
• Abnormal surface enterocytes:
  • Focal crowding -- resembling tufts.

Gangliocytic paraganglioma

• Abbreviated GP.

Main article: Gangliocytic paraganglioma

Pseudomelanosis duodeni

Main article: Pseudomelanosis duodeni

Tumours

Lymphoma

Main article: Lymphoma

• Non-Hodgkin's lymphoma.
  • Enteropathy-associated T-cell lymphoma (EATL) - due to celiac sprue.
  • MALT lymphoma - common GI tract lymphoma.
  • Mantle cell lymphoma.
  • Diffuse large B cell lymphoma.

Note:

• Hodgkin's lymphoma does not arise in the GI tract.

Adenocarcinoma of the duodenum

• AKA duodenal adenocarcinoma.
• AKA duodenal carcinoma.

Main article: Adenocarcinoma of the duodenum

Duodenal neuroendocrine tumour

Main article: Neuroendocrine tumours

General

• Like neuroendocrine tumours elsewhere.
• Use of the term carcinoid is discouraged.

Associations:

• Neurofibromatosis type 1.
• MEN I.

Microscopic

Features:

• Usu. nests of cells - may be:
  • Trabecular.
  • Glandular - common in stomatostatin producing tumours.
• Stippled chromatin - (AKA salt-and-pepper chromatin, coarse chromatin).
• Classically subepithelial/mural.
• +/-Psammoma bodies - suggestive of somatostatinoma and NF1.

DDx:

• Adenocarcinoma of the duodenum.

Images

• 

  Neuroendocrine tumour - low mag. (WC)

• 

  Neuroendocrine tumour - intermed. mag. (WC)

• 

  Neuroendocrine tumour - high mag. (WC)

Ampullary tumours

Main article: Ampullary tumours

General

• Individuals with high-grade dysplasia (on biopsy) are usually treated with a pancreaticoduodenectomy (Whipple procedure), as local resections have a very high recurrence rate.

Microscopic

Features:

• See ampullary tumours.

DDx:

• Intraductal papillary mucinous tumour (IPMT) - a pancreatic tumour, see pancreas article.
• Invasive ductal carcinoma of the pancreas.

Sign out

• Ampullary carcinoma - has separate staging.

Traditional adenoma

Duodenal adenoma redirects here.

Main article: Traditional adenoma

General

• Strong association of familial adenomatous polyposis.
  • In one series of 208 adenomas, almost 70% were from FAP patients.
• Commonly found in association foveolar metaplasia - especially in sporadic cases ~60% of cases.
  • In FAP ~30% of cases have foveolar metaplasia.

Sign out

POLYP, DUODENUM, EXCISION:
- TUBULAR ADENOMA.
-- NEGATIVE FOR HIGH-GRADE DYSPLASIA.

See also

• Gastrointestinal pathology.
• Intestinal polyps.
• Small bowel.

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.