JPC SYSTEMIC PATHOLOGY
DIGESTIVE SYSTEM
October 2018
D-P28

SIGNALMENT (JPC #2550908):  Adult female Barbary ape (Macaca sylvana)

HISTORY:  This animal was kept in a zoo.

HISTOPATHOLOGIC DESCRIPTION:  Liver: Expanding and replacing approximately 50% of the hepatic parenchyma in this section and compressing adjacent hepatocytes is a multilocular alveolar hydatid cyst composed of round to oval to irregular intact and ruptured 2-6 mm diameter cysts surrounded and separated by variably thick bands of fibrous connective tissue that extend into and replace adjacent hepatic parenchyma. Fibrous connective tissue contains moderate numbers of lymphocytes, plasma cells, macrophages and eosinophils, and many entrapped bile ductules.  Cysts are lined by a 10-50 um thick eosinophilic hyaline outer laminated membrane and a 50-150um inner germinal epithelial layer containing basophilic nuclei, eosinophilic flocculant to granular material, and numerous 5-20 um basophilic calcareous corpuscles. Budding from the germinal epithelium or free within the cyst lumen are many thin-walled brood capsules containing multiple 100-150 um diameter protoscolices. Protoscolices have a 5 um thick tegument enclosing spongy parenchyma which contains calcareous corpuscles, a sucker and a rostellum armed with birefringent hooks. Ruptured cysts are collapsed and contain variable amounts of eosinophilic necrotic debris admixed with degenerate neutrophils, eosinophils, lymphocytes, plasma cells, foamy macrophages and multinucleated giant cells, which extend into the adjacent fibrous connective tissue. Multifocally, throughtout the adjacent hepatic parenchyma, hepatocytes are necrotic with shrunken hypereosinophilic cytoplasm and pyknosis, are individualized and surrounded by hemorrhage, are degenerate, with swollen, pale, vacuolated cytoplasm or are lost and replaced by necrotic debris, hemorrhage and/or fibrosis. Portal areas adjacent to the hydatid cyst and areas of hepatocellular necrosis have increased numbers of small bile duct profiles (biliary ductal reaction).

MORPHOLOGIC DIAGNOSIS:  Liver: Hydatid cyst, multiloculated, with multifocal fibrosis, necrotizing hepatitis and biliary hyperplasia, etiology consistent with Echinococcus multilocularis, Barbary ape (Macaca sylvana), primate.

ETIOLOGIC DIAGNOSIS:  Hepatic echinococcosis

CAUSE:  Echinococcus multilocularis

CONDITION:  Alveolar or multilocular hydatid disease

GENERAL DISCUSSION:

PATHOGENESIS:

LIFE CYCLE: 

TYPICAL CLINICAL FINDINGS:

TYPICAL GROSS FINDINGS:

TYPICAL LIGHT MICROSCOPIC FINDINGS:

DIFFERENTIAL DIAGNOSIS: 

COMPARATIVE PATHOLOGY

REFERENCES:

  1. Bowman DD. Georgi's Parasitology for Veterinarians. 9th ed. Philadelphia, PA: Elsevier Saunders; 2009:143-7.
  2. Cerda JR, Ballweber LR. Confirmation of Echinococcus Canadensis G8 and G10 in Idaho Gray Wolves (Canis lupus) and Cervids. J Wildl Dis. 2018 Apr;54(2):403-405.
  3. Christiansen EF, Himsworth CG, Hill JE, et al. Infection of a Goeldi’s Monkey (Callimico Goeldii) With a European Strain of Echinococcus Multilocualris in a Canadian Institution. J Zoo Wildl Med. 2015 Jun;46(2):378-81.
  4. Corsini M, Geissbuhler U, Howard J, Gottsetein B. Clinical presentation, diagnosis, therapy and outcome of alveolar echinococcosis in dogs. Vet Rec. 2015 Nov 4.
  5. Di Paolo A, Piseddu T, Sebastianelli M, et al. Detectin of Echinococcus granulosus G3 in a Wild Boar (Sus scrofa) in Central Italy using PCR and Sequencing. Wildl Dis. 2017 Apr;53(2):399-401.
  6. Gardiner CH, Poynton SL. Morphological characteristics of cestodes in tissue section. In: An Atlas of Metazoan Parasites in Animal Tissues. Washington, DC: Armed Forces Institute of Pathology, American Registry of Pathology; 2006:50-5.
  7. 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; 2017:445-446.
  8. Marty AM, Johnson LK, Neafie RC. Hydatidosis (Echinococcosis). In: Meyers WM, ed. Pathology of Infectious Diseases. Vol 1. Washington, DC: Armed Forces Institute of Pathology, American Registry of Pathology; 2000:145-162.
  9. Strait K, Else JG, Eberhard ML. Parasitic Diseases of Nonhuman Primates. In: Abee CR, Mansfield K, Tardif S, et al. eds. Nonhuman Primates in Biomedical Research: Diseases. Vol 2. 2nd ed. Waltham, MA: Elsevier; 2012: 256-257.
  10. Uzal FA, Platter 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; 2016: 319-320, 556-557.
  11. Weiss AT, Bauer C, Köhler K. Canine alveolar echinococcosis: morphology and inflammatory response. J Comp Pathol. 2010 Nov;143(4):233-8.


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