JPC SYSTEMIC PATHOLOGY

RESPIRATORY SYSTEM

September 2017

P-F03

 

Signalment (WSC 94/95 24-1):  A sea otter (Enhydra lutris)

HISTORY:  This otter was found on the beach near San Diego, California; numerous white lesions throughout the lungs, liver and kidney were found during necropsy.

HISTOPATHOLOGIC DESCRIPTION:  Lung:  Affecting approximately 30% of the pulmonary parenchyma are multiple foci of nodular pyogranulomatous inflammation characterized by large numbers of viable and degenerate neutrophils and epithelioid macrophages admixed with lesser numbers of lymphocytes, plasma cells and rare multinucleated foreign-body macrophages. Poorly-formed granulomas are occasionally centered on individualized 30-80 um diameter spherules which have a 1-3 um thick double contoured, hyaline wall, filled with granular to flocculent, basophilic material or occasionally few 2-5 um round endospores. Inflammatory cells extend into surrounding alveoli, where they are admixed with flocculent eosinophilic edema fluid, and increased numbers of alveolar macrophages. Alveolar septa are expanded up to 3 times normal by macrophages, fewer neutrophils and lymphocytes admixed with fibrin and edema. Multifocally, bronchiolar lumina contain s small amount of exudate composed of viable and degenerate neutrophils, macrophages, hemorrhage, fibrin, edema and necrotic debris. There is multifocal, moderate anthracosilicosis.

MORPHOLOGIC DIAGNOSIS:  Lung:  Pneumonia, pyogranulomatous, multifocal, marked, with rare fungal spherules, etiology consistent with Coccidioides immitis, sea otter (Enhydra lutris), mustelid

ETIOLOGIC DIAGNOSIS:  Pulmonary coccidioidomycosis

CAUSE:  Coccidioides immitis

SYNONYMS:  Valley fever, San Joaquin Valley fever

GENERAL DISCUSSION: 

PATHOGENESIS:  

LIFE CYCLE: 

TYPICAL CLINICAL FINDINGS:

TYPICAL GROSS FINDINGS:

TYPICAL LIGHT MICROSCOPIC FINDINGS: 

ULTRASTRUCTURAL FINDINGS:

ADDITIONAL DIAGNOSTIC TESTS:

DIFFERENTIAL DIAGNOSIS: 

Organisms that produce spherule-like structures:

Dimorphic fungal infections:

Organisms that reproduce by endosporulation:

COMPARATIVE PATHOLOGY:

REFERENCES: 

  1. Ajithdoss DK, et al. Coccidiomycosis presenting as a heart base mass in two dogs. J Comp Pathol. 2011; 145(2-3): 132-137
  2. Caswell JL, Williams KJ. The respiratory system. In: Maxie MG, ed. Jubb, Kennedy, and Palmer’s Pathology of Domestic Animals, Vol 2, 6th ed. St. Louis, MO: Elsevier; 2016:583-584
  3. Huckabone SE, et al. Coccidioidomycosis and other systemic mycoses of marine mammals stranding along the central California, USA coast: 1998-2012. J Wildl Dis. 2015; 51(2):295-308
  4. Jang SS, et al. In: Greene CE, ed. Coccidioidomycosis and paracoccidioidomycosis. Infectious diseases of the dog and cat, 4th ed. St. Louis, MO: Elsevier; 2012: 634-644
  5. Lopez A, et al. Respiratory system, mediastinum and pleurae. In: Zachary JF, ed. Pathologic Basis of Veterinary Disease. 6th St. Louis, MO: Mosby Elsevier; 2016:547-548
  6. Miller RE, et al. Fowler’s Zoo and Wild Animal Medicine, Vol 8. St. Louis, MO: Elsevier; 2015: 329,562-565,600
  7. Sherman A, et al. What is your diagnosis. J Amer Vet Med Assoc. 2014; 245(12):1331-1333
  8. Shubitz LF, et al. T-lymphocyte predominance in lesions of canine coccidioidomycosis. Vet Pathol. 2011; 48(5):1008-1011
  9. Simoes DM, et al. Retrospective analysis of cutaneous lesions in 23 canine and 17 feline cases of coccidioidomycosis seen in Arizona, USA (2009–2015). Vet Dermatol. 2016; 27 (5): 346-352
  10. Zachary JF. Mechanisms of microbial infections. In: Zachary JF, ed. Pathologic Basis of Veterinary Disease. 6th St. Louis, MO: Mosby Elsevier; 2016: 231, 234


Click the slide to view.



Click on image for diagnostic series.



Back | Home | Contact Us | Links | Help |