Duodenum

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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.
  • No organisms in lumen.

DDx:

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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.

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.[2]

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[3]

Common:

Rare:

Common stuffs

Gastric heterotopia of the duodenum

  • AKA heterotopic gastric mucosa.

General

Microscopic

Features:

  1. Foveolar epithelium.
  2. Gastric glands - body-type or antral-type.

DDx:

  • Foveolar metaplasia.

Images

www:

Sign out

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

Celiac sprue

General

  • Etiology: autoimmune.

Epidemiology

  • Associated with:
    • The skin condition dermatitis herpetiformis.[6]
    • IgA deficiency - 10-15X more common in celiac disease vs. healthy controls.[7]
    • 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:[8]

  • Intraepithelial lymphocytes (IELs) - key feature.
    • Should be more pronounced at tips of villi.[9]
    • Criteria for number varies:
      • > 40 IELs / 100 enterocytes (epithelial cells).[10]
      • > 25 IELs / 100 enterocytes (epithelial cells).[11]
  • 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

General

  • Etiology:
    • Flagellate protozoan Giardia lamblia.
  • Treatment
    • Antibiotics, e.g. metronidazole (Flagyl).

Gross

  • Diffuse changes.

Microscopic

Features:

  • +/-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.[12]
      • Often look like a crescent moon (image of crescent moon) or semicircular[13] -- as the long axis of the organism is rarely in the plane of the (histologic) section.

Note:

  • Changes are typically diffuse, i.e. if multiple biopsies are done the changes are present in all fragments.[14]

DDx:

Images:

Sign out

DUODENUM, BIOPSY:
- SMALL BOWEL MUCOSA WITH BRUNNER'S GLANDS AND MICROORGANISMS CONSISTENT WITH GIARDIA.

Acute duodenitis

  • Abbreviated AD.

General

DDx:

Microscopic

Features:

  • Intraepithelial lymphocytes.
  • Neutrophils - "found without searching" - key feature.
  • Eosinophils - "found without searching" - key feature.
  • Plasma cells (increased).

Notes:

  • One needs stomach concurrent biopsies to r/o Helicobactor.
  • Erosions make celiac sprue much less likely.
  • Presence of chronic inflammation useful for NSAIDs vs. Helicobacter organisms:
    • NSAIDs not commonly assoc. with acute inflammation;[16] thus, without chronic inflammation NSAIDs are unlikely.
      • Acute NSAID-related duodenitis reported.[17]

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DUODENUM, BIOPSY:
- ACUTE DUODENITIS.

Acute on chronic duodenitis

DUODENUM, BIOPSY:
- ACUTE ON CHRONIC DUODENITIS.
Micro

The sections show small bowel mucosa with intraepithelial neutrophils. The epithelium shows nuclear hyperchromasia, pseudostratification and nuclear enlargement; however, it matures toward the surface (reactive changes of the epithelium).

Brunner's glands are found focally in the lamina propria. Gastric foveolar-type epithelium is identified. Lamina propria plasma cells are abundant.

Chronic duodenitis

General

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

Gross

  • Duodenal erythema.

Microscopic

Features:

DDx:

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.[5]

Microscopic

Features:[18]

DDx:

Images

Stains

Foveolar metaplasia:

Sign out

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.

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 MALIGNANCY.
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.[19]

General

  • Benign.
  • Usually asymptomatic.[20]

Note:

  • The AFIP uses the term Brunner's gland hamartoma for lesions > 5 mm.[21]
    • 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.[22]
  • +/-Pancreatic acini and ducts.[21]

DDx:

Image:

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.

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.[23]
    • Maltase and sucrase only affected in moderate and severe lesions.

Microscopic

Features:[23]

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

DDx:

Notes:

  • May have normal histomorphology.[23]

Whipple disease

General

Etiology:

  • Infection - caused by Tropheryma whipplei[25] a rod-shaped organisms.[26]

Epidemiology:

  • Very rare.
  • Classically middle aged men.

Clinical

  • Malabsorption (diarrhea), arthritis + others.
    • Symptoms are non-specific.

Treatment:

  • Antibiotics - for months and months.

Microscopic

Features:[27]

  • Infectious microorganism typically found in macrophages.
    • Macrophages usually abundant - key feature that should raise Dx in DDx.
    • Organisms periodic acid-Schiff (PAS) positive.

DDx:

Images:

Stains

  • PAS +ve organisms.
  • AFB stain -ve -- to r/o MAI.

Image:

Microvillous inclusion disease

This rare disease presents very shortly after birth.

Tufting enteropathy

  • AKA intestinal epithelial dysplasia.

General

  • Genetic disease[28] - related to abnormal enterocytes (development and/or differentiation).
    • Gene implicated: EPCAM.[29]

Microscopic

Features:[30]

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


Gangliocytic paraganglioma

  • Abbreviated GP.

General

Clinical - presentation:[34]

  • GI bleed ~ 45% of cases.
  • Abdominal pain ~ 43% of cases.
  • Anemia ~ 15% of cases.

Gross

  • Classically in the duodenum ~90% of cases.[34]

Microscopic

Features - three components:[35][36]

  1. Ganglion cells = large cells with:
    • Round large nucleus.
    • Prominent nucleolus.
    • Moderate or abundant cytoplasm.
  2. Epithelioid cells (neuroendocrine component):
    • Arranged in nests or cords.
    • Stippled chromatin.
  3. Spindle cells (schwannian component):
    • Moderate or abundant cytoplasm.
    • Nucleus spindle-shaped or ellipsoid.

DDx:[35]

Images:

IHC

  • Synaptophysin +ve.
  • CD56 +ve.
  • Chromogranin A +ve.
  • HU +ve in ganglion-like cells.
  • S100 +ve in spindle cells & sustentacular cells.

Pseudomelanosis duodeni

General

  • Rare.
  • Consists of iron and lipofuscin.[38]

Associations:[39]

  • Hypertension ~90% of cases.
  • Iron supplementation ~75% of cases.
  • End-stage renal disease ~60% of cases.

Note:

Gross/endoscopic

  • Dark spots ~35% of cases.[39]

Microscopic

Features:

  • Dark pigment in the lamina propria macrophages.

Images:

Stains

  • Prussian blue +ve ~80% of cases.[39]

Tumours

Lymphoma

Note:

Adenocarcinoma of the duodenum

  • AKA duodenal adenocarcinoma.
  • AKA duodenal carcinoma.

General

Risk factors:

Gross

  • Mass ulcerating or exophytic.

Image:

Microscopic

Features:

DDx:

IHC

Duodenal neuroendocrine tumour

General

Associations:

Microscopic

Features:[44]

  • 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.[45]

DDx:

Images:

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.[46]

Microscopic

Features:

DDx:

Sign out

  • Ampullary carcinoma - has separate staging.

See also

References

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  2. El-Zimaity. 18 October 2010.
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External links

Review article(s)