JPC SYSTEMIC PATHOLOGY
SPECIAL SENSES SYSTEM
April 2018
S-F01 (NP)

Signalment (JPC #1743577):  Labrador mix

HISTORY:  This Labrador mix developed neurological signs including papillitis, which eventually progressed to blindness.  At necropsy, the animal also had meningitis.

HISTOPATHOLOGIC DESCRIPTION:  Eye: Expanding the optic nerve meninges, surrounding the nerve, and extending into perineural adipose tissue are numerous epithelioid macrophages, fewer lymphocytes and plasma cells, occasional multinucleated giant cells, and rare neutrophils. There are numerous extracellular and intrahistiocytic, round to crescentic, non-staining, 5-20 um diameter yeast, with thin, birefringent walls and rare narrow-based budding. Yeasts are surrounded by a clear, 5-10 um wide halo. Focally within the choroid, there is a single, 70 by 80 um nodule composed of moderate numbers of previously described inflammatory cells and yeast that elevates the retinal pigmented epithelium. 

MORPHOLOGIC DIAGNOSIS:  Eye, optic nerve:  Meningitis, granulomatous, diffuse, moderate, with focal choroiditis, perineural steatitis, and myriad yeast, etiology consistent with Cryptococcus neoformans, Labrador mix, canine.

ETIOLOGIC DIAGNOSIS:  Ocular cryptococcosis

CAUSE:  Cryptococcus neoformans

SYNONYM:  European blastomycosis, torulosis

GENERAL DISCUSSION: 

PATHOGENESIS:

TYPICAL CLINICAL FINDINGS:

TYPICAL GROSS FINDINGS:

TYPICAL LIGHT MICROSCOPIC FINDINGS:

ADDITIONAL DIAGNOSTIC TESTS:

DIFFERENTIAL DIAGNOSIS:

Causes of Fungal/Algal Intraocular Infections:

COMPARATIVE PATHOLOGY:

References:

  1. Caswell JL, Williams KJ. Respiratory system. . In: Maxie MG, ed. Jubb, Kennedy, and Palmer’s Pathology of Domestic Animals. 6th ed. Vol 2. St. Louis, MO: Elsevier Limited; 2016:582-583.
  2. Duncan CG, Stephen C, Campbell J. Evaluation of risk factors for Cryptococcus gattii infection in dogs and cats. J Am Vet Med Assoc. 2006;228:377-382.
  3. Gionfriddo JR. Feline systemic fungal infections. Vet Clin North Am Small Anim Pract. 2000;30:1029-1050.
  4. Johnson KL, James MD, Carrera-Justiz S. What is your neurologic diagnosis?. J Am Vet Med Assoc. 2017;251(6):653-656.
  5. Jones TC, Hunt RD, King NW. Veterinary Pathology. 6th ed. Baltimore, MD: Williams & Wilkins;1997: 16-517.
  6. Krohne SG. Canine systemic fungal infections. Vet Clin North Am Small Anim Pract. 2000;30:1063-1090.
  7. Labelle P. The eye. In: McGavin MD, Zachary JF, eds. Pathologic Basis of Veterinary Disease. 6th ed. St. Louis, MO: Mosby; 2016:1301.
  8. Martinez-Nevado E, Alonso-Alegre EG, Martinez A, et al. Atypical presentation of Cryptococcus neoformans in a koala (Phascolarctos cinereus) a magnetic resonance imaging and computed tomography study. Journal of Zoo and Wildlife Medicine. 2017;48(1):250-254.
  9. Myers A, Meason-Smith C, Mansell J, et al. Atypical cutaneous cryptococcosis in four cats in the USA. Veterinary Dermatology. 2017;28:405-e97.
  10. Rosenberg JF, Haulena M, Hoang LMN, et al. Cryptococcus gattii Type VGIIa infection in harbor seals (Phoca vitulina) in British Columbia, Canada. Journal of Wildlife Diseases. 2016;52(3):677-681.
  11. Sykes JE, Malik R. Cryptococcosis. In: Greene CE, ed. Infectious Diseases of the Dog and Cat. 4th ed. St. Louis, MO: Elsevier Inc.; 2012:621-634.
  12. Wilcock BP, Njaa BL. Special senses. In: Maxie MG, ed. Jubb, Kennedy, and Palmer’s Pathology of Domestic Animals. 6th ed. Vol 1. St. Louis, MO: Elsevier Inc; 2016:450.

 


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