JPC SYSTEMIC PATHOLOGY
DIGESTIVE SYSTEM
September 2021
D-M03 (NP)

 

SIGNALMENT (JPC #1758202): 7-year old German shepherd dog

HISTORY: Incidental finding

MICROSCOPIC DESCRIPTION: Stomach, fundus: Multifocally, mucosal epithelial cells are markedly hyperplastic, forming additional rugal folds between pre-existing gastric furrows and markedly thickening gastric pits. Hyperplastic cells pile up to five layers thick and demonstrate mild anisokaryosis. The subepithelial lamina propria is expanded by multifocal aggregates of lymphocytes and plasma cells that often transmigrate the gastric mucosal epithelium.

MORPHOLOGIC DIAGNOSIS: Stomach, fundus, epithelial mucosa: Hyperplasia, multifocal, chronic, moderate, with lymphoplasmacytic infiltration, German shepherd, canine.

ETIOLOGY: Unknown

CONDITION: Chronic hypertrophic gastritis

GENERAL:

• Idiopathic condition of dogs
• An umbrella term that covers several entities with distinctly different histologic appearances and behaviors
  • Menetrier-like disease
  • Zollinger-Ellison syndrome-like disease

PATHOGENESIS:

• Unknown
• The cause in dogs is unknown but may be due to:
  • Immune mediated response to underlying food intolerances
  • Chronic irritation from retained gastric fluid and reflux of bile
  • Possibly heritable
• Possible association with gastric adenocarcinoma (Munday, Vet Pathol, 2012)
• One reported case of Ménétrier-like disease in a Labrador retriever with concurrent gastric sarcoma (Romanucci, J Vet Diagn Invest, 2021)
• In the analogous Ménétrier's disease in humans, gastric mucosal proliferation is associated with excessive secretion of TGF-α (an EGF receptor) ligand

TYPICAL CLINICAL FINDINGS:

• Vomiting and weight loss, in some cases associated with inappetence or diarrhea

TYPICAL GROSS FINDINGS:

• Exaggerated or thickened rugal folds (over an area 4-10 cm in diameter) in the fundic region
• Pyloric hypertrophy
• Marked cystic dilation of mucous glands

TYPICAL MICROSCOPIC FINDINGS:

• Foveolar and glandular epithelial hyperplasia
  • +/- progressive or total loss of parietal cells, which are replaced by mucous cells of various degrees of differentiation (Ménétrier-like disease)
  • +/- hyperplasia and hypertrophy of parietal cells that crowd out chief cells and mucous neck cells (Zollinger-Ellison syndrome-like disease)
  • Lymphoplasmacytic infiltration
• Mononuclear cells infiltrating the lamina propria between glands and near the muscularis mucosae with superficial edema

ADDITIONAL DIAGNOSTIC TESTS:

• Gastroscopy/laparotomy with histopathology (full thickness biopsies preferred)
• Radiographic contrast studies for outflow obstruction

DIFFERENTIAL DIAGNOSIS:

• Hypertrophic pyloric gastropathy: Small breed dogs; focal, eosinophilic infiltrate
• Adenomatous polyps: Raised, sessile, or pedunculated polypoid masses
• Paraneoplastic syndromes from excess gastrin; ulcers may be present:
  • Mast cell tumors
  • Renal dysfunction
  • Pancreatic islet cell tumors (Zollinger-Ellison syndrome)
  • Gastrinomas
• Lymphoma: Sheets of lymphocytes
• Leiomyoma: No inflammatory infiltrate, well demarcated
• Giant hypertrophic gastritis (Ménétrier’s disease in humans):
  • Basenji, Beagle, Boxer, Bull terrier, Cairn terrier
  • Diffuse cerebriform mass of redundant mucosa
  • The histology typically shows elongated, tortuous foveolae, with reduction of chief and parietal cell glands and often with cystic dilatations that may extend into muscularis mucosae and submucosa
  • Present with hypoproteinemia

COMPARATIVE PATHOLOGY:

Hypertrophic gastritis in other species:

• Humans: Unproven etiology of Ménétrier's disease; some human cases have association with pylori or viral agents; there is an association between cytomegaloviral (HCMV) infection prior to the development of Ménétrier's disease in human children
• Non-human primates: Hypertrophic gastritis in SIV-infected macaques has been associated with cytomegaloviral infection (CMV) (Hutton, Vet Pathol, 2004)

Parasitic gastritis that may cause hypertrophic gastritis:

• Non-human primates: Nochtia nocti
• Cattle: Ostertagia ostertagi
• Sheep: Ostertagia circumcincta
• Horse: Trichostrongylus axei; Habronema
• Pig: Hyostrongylus rubidus
• Cat: Ollulanus tricuspis

REFERENCES:

1. Gelberg HB. Alimentary system and the peritoneum, omentum, mesentery, and peritoneal cavity. In: Zachary JF, ed. Pathologic Basis of Veterinary Disease. 6th ed. St. Louis, MO: Elsevier; 2017:363.
2. Hutto EH, Anderson DC, Mansfield KG. Cytomegalovirus-associated discrete gastrointestinal masses in macaques infected with simian immunodeficiency virus. Vet Pathol. 2004;41:691-695.
3. Kumar V, Abbas AK, Aster JC, eds. The Gastrointestinal Tract. In: Robbins and Cotran Pathologic Basis of Disease, 10^th Philadelphia, PA:Elsevier. 2021: 771-772.
4. Munday JS, Aberdein D, Cullen GD, French AF. Ménétrier disease and gastric adenocarcinoma in 3 Cairn terrier littermates. Vet Pathol. 2012;49(6):1028-1031.
5. Romanucci M, Crisi PE, Giordana MV, Di Tommaso M, Simeoni F, Della Salda L. Hypertrophic gastropathy associated with gastric sarcoma in a dog. J Vet Diagn Invest. 2021;33(1):112-115.
6. Uzal FA, Plattner BL, Hostetter JM. Alimentary system. In: Maxie MG, ed. Jubb, Kennedy, and Palmer’s Pathology of Domestic Animals. Vol 2. 6th ed. St. Louis, MO: Elsevier Ltd; 2016:53, 100-101.

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