Autoimmune metaplastic atrophic gastritis

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Autoimmune metaplastic atrophic gastritis
Diagnosis in short

Atrophic gastritis (body) without appreciable parietal cells. H&E stain.

LM corpus predominant inflammation - usu. moderate or severe, loss of parietal cells, increased G cells in the antrum
LM DDx chronic gastritis, intestinal metaplasia of the stomach, gastric neuroendocrine tumour
Site stomach

Prevalence uncommon
Blood work antibodies to parietal cells & intrinsic factor, macrocytic anemia, increased gastrin level
Endoscopy erythema - corpus only
Clin. DDx diffuse chronic gastritis

Autoimmune metaplastic atrophic gastritis, also autoimmune gastritis[1] (abbreviated AIG), is a rare pathology of the stomach. It is closely associated with pernicious anemia.

General

  • Pathology: loss of parietal cells, gastric atrophy.
  • Lab: classically considered to have macrocytic anemia; however, normocytic and microcystic more common.[2]
  • Etiology: autoimmune.

Diagnosis based on serology for antibodies to:[3]

  • Parietal cells.
  • Intrinsic factor.

Others:

  • Gastrin level (increased).[4]
    • Normal < 100 pg/mL.[5]

Note:

  • Parietal cells produce intrinsic factor (important for vitamin B12 absorption) and hydrogen chloride, i.e. stomach acid.

Gross

  • Erythema - corpus involved, antrum spared.

Microscopic

Features:

  • Corpus predominant inflammation - usu. moderate or severe - key feature.
  • Loss of parietal cells.
  • Increased G cells in the antrum.
    • Produce gastrin to stimulate the (missing) parietal cells.

Notes:

DDx:

Images

IHC

Features:[6]

  • Chromogranin A +ve (demonstrates nodular enterochromaffin-like cell hyperplasia).
  • Gastrin -ve (body of stomach).
    • +ve in antrum.

Images

Body

Antrum

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Stomach, Body, Biopsy:
     - Gastric mucosa with INTESTINAL METAPLASIA, 
       moderate chronic inactive inflammation and atrophic features, SEE COMMENT.
     - NEGATIVE for apparent parietal cells, SEE COMMENT.
     - NEGATIVE for Helicobacter-like organisms.
     - NEGATIVE for dysplasia and NEGATIVE for malignancy.

Comment:
Immunostains show rows of Chromogranin A positive cells and a lack of gastrin staining.  

These findings suggest an autoimmune (metaplastic atrophic) gastritis; correlation with blood work and clinical findings is recommended.

Block letters

STOMACH, BIOPSY:
- SEVERE CHRONIC ACTIVE GASTRITIS WITH EXTENSIVE INTESTINAL METAPLASIA.
- NEGATIVE FOR HELICOBACTER-LIKE ORGANISMS.
- NEGATIVE FOR DYSPLASIA AND NEGATIVE FOR MALIGNANCY.

COMMENT:
Parietal cells are not apparent on the H&E stained sections. Immunostains show 
rows of Chromogranin A positive cells and a lack of gastrin staining.  

These findings suggest an autoimmune gastritis; correlation with blood work 
is suggested.

See also

References

  1. Chlumská, A.; Boudová, L.; Benes, Z.; Zámecník, M. (Oct 2005). "Autoimmune gastritis. A clinicopathologic study of 25 cases.". Cesk Patol 41 (4): 137-42. PMID 16382988.
  2. Hershko, C.; Ronson, A.; Souroujon, M.; Maschler, I.; Heyd, J.; Patz, J. (Feb 2006). "Variable hematologic presentation of autoimmune gastritis: age-related progression from iron deficiency to cobalamin depletion.". Blood 107 (4): 1673-9. doi:10.1182/blood-2005-09-3534. PMID 16239424.
  3. Oh, R.; Brown, DL. (Mar 2003). "Vitamin B12 deficiency.". Am Fam Physician 67 (5): 979-86. PMID 12643357.
  4. Annibale, B.; Lahner, E.; Fave, GD. (Dec 2011). "Diagnosis and management of pernicious anemia.". Curr Gastroenterol Rep 13 (6): 518-24. doi:10.1007/s11894-011-0225-5. PMID 21947876.
  5. URL: http://www.mayomedicallaboratories.com/test-catalog/Clinical+and+Interpretive/8512. Accessed on: 14 August 2012.
  6. Park, JY.; Cornish, TC.; Lam-Himlin, D.; Shi, C.; Montgomery, E. (Nov 2010). "Gastric lesions in patients with autoimmune metaplastic atrophic gastritis (AMAG) in a tertiary care setting.". Am J Surg Pathol 34 (11): 1591-8. doi:10.1097/PAS.0b013e3181f623af. PMID 20975338.
  7. Pritchard, DM.; Berry, D.; Przemeck, SM.; Campbell, F.; Edwards, SW.; Varro, A. (Oct 2008). "Gastrin increases mcl-1 expression in type I gastric carcinoid tumors and a gastric epithelial cell line that expresses the CCK-2 receptor.". Am J Physiol Gastrointest Liver Physiol 295 (4): G798-805. doi:10.1152/ajpgi.00015.2008. PMID 18719002.