JPC SYSTEMIC PATHOLOGY
Signalment (JPC Accession # 4070541): 9-month-old, intact female Persian cat
HISTORY: This cat had a history of intermittent vomiting and failure to gain weight. Abdominal radiographs revealed a mass at the gastric pylorus. Exploratory laparotomy revealed a thickened gastric pylorus region characterized by a thickened wall and roughened mucosal surface.
HISTOPATHOLOGIC DESCRIPTION: Stomach, pylorus: Affecting 90% of this section, the wall of the pylorus is transmurally effaced by a mass-forming proliferation of innumerable large, plump fibroblasts arranged in long, interlacing streams and bundles. Fibroblasts have large oval nuclei with finely stippled chromatin, prominent nucleoli, and up to 3 mitoses per 10 HPF. Thick bands of branching and anastomosing fibrous connective tissue with variable maturity from loose and immature to dense and sclerotic are arrayed in a herringbone pattern throughout the mass. Admixed are large numbers of eosinophils and fewer macrophages and plasma cells. Within the overlying/adjacent mucosa, gastric glands are decreased in number and often dilated, and the lamina propria is expanded by increased amounts of fibrous connective tissue and slightly increased numbers of lymphocytes, plasma cells, histiocytes, and eosinophils. The interface between the remaining mucosa and the fibrous mass is composed of a large bed of granulation tissue which blends imperceptibly with the advancing front of the fibrous mass. At the edges of the fibrous mass, muscle fibers of the muscular tunics are shrunken and hypereosinophilic (atrophy and necrosis), and are surrounded by infiltrating fibrous connective tissue. Fibrous connective tissue infiltrates and expands perivascular tissue throughout much of the remaining muscular tunics. There are multiple lymphoid nodules within the serosa, and serosal vessels are often surrounded by edema and moderate numbers of eosinophils and lymphocytes.
MORPHOLOGIC DIAGNOSES: Stomach: Gastritis, ulcerative, eosinophilic, and sclerosing, transmural, focally extensive, marked, Persian, feline.
CONDITION: Feline gastrointestinal eosinophilic sclerosing fibroplasia (FGESF); scirrhous eosinophilic gastritis
- A recently described (2009) feline inflammatory condition affecting the gastrointestinal tract and associated lymph nodes
- Primarily affects middle-aged cats
- Not completely understood etiopathogenesis, suggestions include:
- Immunologic dysregulation triggered by one of multiple possible causes (parasitism, food allergy, dysbiosis, IBD, inherited genetic mutation leading to eosinophil dysregulation)
- Presence of bacteria (gram positive cocci and gram negative bacilli embedded within sclerotic collagen of the lesion) have been associated with lesions; antibiotic therapy is not effective in treating the condition
- Presence of fungi (Grau-Roma et. al. 2014)
- Presence of Toxoplasma gondii
- Presence of alimentary nematode Cylicospirura in a free-ranging puma
- No infectious etiology was reported in nearly half of cases in one report
- Eosinophils elaborate major basic protein, TGF-β, IL-1B, and IL-6 (and more) à repetitive cycle of tissue destruction and fibrosis
TYPICAL CLINICAL FINDINGS:
- Digestive signs including persistent emesis, weight loss, and malnutrition
- An abdominal mass is frequently palpated or found on abdominal imaging
- Clinical pathology: hyperproteinemia associated with hyperglobulinemia, hypoalbuminemia, +/- peripheral eosinophilia, mild peripheral neutrophilia
TYPICAL GROSS FINDINGS:
- Typically an ulcerated gastrointestinal intramural nodular mass effacing the gastrointestinal wall, most commonly found at the pyloric sphincter or ileocecocolic junction, but may be found anywhere along the intestines
TYPICAL LIGHT MICROSCOPIC FINDINGS:
- Characteristic pattern of a network of coarse collagen trabeculae admixed with large spindle cells (myofibroblasts) mixed with predominantly eosinophilic inflammation
- Fibroplasia and inflammation extensively infiltrate the intestinal wall (may be transmural) and sometimes extend to regional lymph nodes
- Intestinal mucosa is frequently ulcerated
- Gross appearance: neoplasia (lymphoma, fibrosarcoma, adenocarcionoma), granuloma
- Histologic appearance: neoplasia (fibrosarcoma, extraskeletal osteosarcoma [sclerotic collagen misinterpreted as osteoid], feline sclerosing mast cell tumor, lymphoma [sclerosing variant])
- Eosinophilic gastritis, 3 forms in dogs and cats:
- Focal eosinophilic infiltrate in dogs and cats is sometimes associated with trapped intramural nematode larvae, due to antigenicity of nematode larval sheath, feces, and saliva; tissue reaction results in gastric epithelial cell hyperplasis resulting in polyp-like proliferation of antral mucosa; especially Toxocara canis (dogs)
- Diffuse eosinophilic infiltrate is believed to be a hypersensitivity reaction to an unknown antigen, often with associated peripheral eosinophilia and intestinal eosinophilia; eosinophilic inflammation may become transmural with necrosis and scarring, and may be associated with visible hypertrophy of the tunica muscularis
- Scirrhous eosinophilic gastritis of dogs and cats
- This condition is unique to felids; other than domestic cats, it has been recognized in pumas in association with Cylicospirura , although the puma lesions had fewer eosinophils
- Brosinski K, Burkhardt WA, Venzin C, Grest P. Diagnostic exercise: submucosal gastric masses in a cat. Pathol. 2013;50(2):350-353.
- Craig LE, Hardam EE, Hertzke DM, et al. Feline Gastrointestinal eosinophilic sclerosing fibroplasia. Vet Pathol. 2009;46(1):63-70.
- Eckstrand CD, Barr BC, Woods LW, Spangler T, Murphy B. Nematode-associated intramural alimentary nodules in pumas are histologically similar to gastrointestinal eosinophilic sclerosing fibroplasia of domestic cats. Pathol. 2013;148:405-409.
- Gelberg HB. Alimentary system and the peritoneum, omentum, mesentery, and peritoneal vacity. In: Zachary JF, ed. Pathologic Basis of Veterinary Disease. 6th ed. St. Louis, MO: Elsevier; 2017:362-363.
- Grau-Roma L, Galindo-Cardiel I, Isidoro-Ayza M, Fernandez M, Majo N. A case of feline gastrointestinal eosinophilic sclerosing fibroplasia associated with phycomycetes. Pathol. 2014;151:318-321.
- 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. Philadelphia, PA: Elsevier Saunders; 2016:96.