JPC SYSTEMIC PATHOLOGY

INTEGUMENT SYSTEM

August 2016

I-F07

Signalment (JPC #1380452):  Adult male Siamese cat

HISTORY:  This cat presented with a small circular raised nodule on its head.  Similar, occasionally ulcerated nodules later developed on the head, ears, nose and forelimbs.  The animal was euthanized and this section taken from the ear at the time of necropsy.

HISTOPATHOLOGIC DESCRIPTION:  Haired skin, pinna:  Infiltrating the dermis, separating and effacing adnexa, and elevating a mildly hyperplastic epidermis are multiple coalescing nodules composed of numerous macrophages and neutrophils with fewer perivascular and periadnexal lymphocytes and plasma cells.  There are numerous intrahistiocytic and extracellular 4-10 um diameter, round to oval, lightly eosinophilic yeast that are occasionally surrounded by a clear halo.  The epidermis is focally ulcerated and mildly hyperplastic, with acanthosis and spongiosis.  There is rare neutrophilic exocytosis.

PAS:  There are numerous intrahistiocytic and extracellular pleomorphic (round, oval and occasional cigar-shaped) PAS-positive yeast.

MORPHOLOGIC DIAGNOSIS:  Haired skin, pinna:  Dermatitis, pyogranulomatous, nodular, multifocal, moderate, with numerous intrahistiocytic and extracellular PAS-positive yeast, etiology consistent with Sporothrix schenckii, Siamese, feline.

ETIOLOGIC DIAGNOSIS:  Aural cutaneous sporotrichosis

CAUSE:  Sporothrix schenckii

GENERAL DISCUSSION: 

PATHOGENESIS: 

TYPICAL CLINICAL FINDINGS: 

TYPICAL GROSS FINDINGS: 

TYPICAL LIGHT MICROSCOPIC FINDINGS: 

 ADDITIONAL DIAGNOSTIC TESTS: 

 DIFFERENTIAL DIAGNOSIS: 

Gross findings: 

Solitary (or multiple) ulcerated and fistulated dermal lesions in cats and dogs: 

Cutaneous equine lymphangitis with draining tracts: 

Histologic findings: 

COMPARATIVE PATHOLOGY: 

REFERENCES:

  1. Crothers SL, White SD, Ihrke PJ, Affolter VK. Sporotrichosis: a retrospective evaluation of 23 cases seen in northern California (1987-2007). Vet Dermatol. 2009;20(4):249-259.
  2. Gross TL, Ihrke PJ, Walder EJ, Affolter, VK eds. Skin Diseases of the Dog and Cat- Clinical and Histopathologic Diagnosis. 2nd ed. Ames, IA: Blackwell Science Ltd.; 2005: 298-301.
  3. Hargis AM, Ginn PE. The integument. In: McGavin MD, Zachary JF, eds. Pathologic Basis of Veterinary Disease. 5th ed. St. Louis, MO: Mosby Elsevier; 2007: 1040.
  4. Jang SS, Walker RL. Fungal and algal diseases. In: Greene CE, ed. Infectious Diseases of the Dog and Cat. 4th ed. St. Louis, MO: Elsevier Saunders; 2012: 645-650.
  5. Mauldin EA, Peters-Kennedy J. Integumentary system. In: Maxie MG, ed. Jubb, Kennedy, and Palmer’s Pathology of Domestic Animals. Vol 1. 6th ed. St. Louis, MO: Elsevier; 2016: 655-657.
  6. Miranda LH, Quintella LP, Santos IB, et al. Comparative histopathological study of sporotrichosis and American tegumentary leishmaniasis in dogs from Rio de Janeiro. J Comp Pathol. 2010;143(1):1-7.
  7. Schubach TM, Schubach A, Okamoto T, et al. Evaluation of an epidemic of sporotrichosis in cats: 347 cases (1998-2001). J Am Vet Med Assoc. 2004:224(10):1623-1629.
  8. Scott DW, Miller WH Jr, eds. Equine Dermatology. St. Louis, MO: Elsevier Science; 2003: 296-298.


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