title: Atypical cutaneous cryptococcosis in four cats in the USA.
abstract: BACKGROUND
  Cryptococcosis is an uncommon fungal infection in humans and mammals. Occasionally, cryptococcosis manifests as cutaneous lesions, either as an extension of nasal disease or as stand alone lesions unassociated with the nose. Histologically, these lesions are typically characterized by abundant organisms with mild granulomatous dermatitis. Herein, four feline cases of atypical cutaneous cryptococcal infections are described.
  
  
  METHODS
  Skin punch biopsies from four client owned cats were submitted for histological evaluation between 2006 and 2015. Histological examination, including histochemical stains, was performed in all cases. Immunohistochemical stains and PCR were performed in three of four cases. Fungal culture was performed in two cases and transmission electron microscopy was performed in one case.
  
  
  RESULTS
  Grossly, the cutaneous lesions were papular to nodular with occasional ulceration and were located predominantly on the trunk. Histological examination revealed severe granulomatous to pyogranulomatous and eosinophilic dermatitis with rare, capsule-deficient yeasts. Immunohistochemistry, PCR and fungal culture confirmed Cryptococcus spp. to be the aetiological agent in these cases.
  
  
  CONCLUSIONS
  In cutaneous lesions, capsule-deficient strains of Cryptococcus spp. may induce a severe inflammatory response with rare intralesional organisms that may not be readily identified on routine haematoxylin and eosin stained slides. Special stains with careful examination and ancillary tests (PCR, immunohistochemistry, fungal culture or antigen testing) should be performed when pyogranulomatous and eosinophilic dermatitis is encountered without an identifiable cause.
authors.affiliation: Department of Veterinary Pathobiology, College of Veterinary Medicine & Biomedical Science, Texas A&M University, College Station, TX, 77843, USA.
authors.forename: Alexandra
authors.identifier: http://orcid.org/0000-0002-2680-6526
authors.initials: A
authors.lastname: Myers
authors.affiliation: Department of Veterinary Pathobiology, College of Veterinary Medicine & Biomedical Science, Texas A&M University, College Station, TX, 77843, USA.
authors.forename: Courtney
authors.identifier: http://orcid.org/0000-0002-5189-2702
authors.initials: C
authors.lastname: Meason-Smith
authors.affiliation: Dermatopathology Specialty Service, College of Veterinary Medicine & Biomedical Science, Texas A&M University, College Station, TX, 77843, USA.
authors.forename: Joanne
authors.initials: J
authors.lastname: Mansell
authors.affiliation: Faculty of Veterinary Science, University of Sydney, Sydney, New South Wales, 2006, Australia.
authors.forename: Mark
authors.initials: M
authors.lastname: Krockenberger
authors.affiliation: Department of Biomedical Science, College of Veterinary Medicine, Cornell University, Ithaca, NY, 14850, USA.
authors.forename: Jeanine
authors.initials: J
authors.lastname: Peters-Kennedy
authors.affiliation: Department of Veterinary Pathobiology, College of Veterinary Medicine & Biomedical Science, Texas A&M University, College Station, TX, 77843, USA.
authors.forename: Harold
authors.initials: H
authors.lastname: Ross Payne
authors.affiliation: Dermatopathology Specialty Service, College of Veterinary Medicine & Biomedical Science, Texas A&M University, College Station, TX, 77843, USA.
authors.forename: Aline
authors.initials: A
authors.lastname: Rodrigues Hoffmann
mesh_terms: D000818:Animals; D001706:Biopsy / Q000662:veterinary; D002371:Cat Diseases / Q000175:diagnosis / Q000382:microbiology* / Q000473:pathology; D002415:Cats; D003453:Cryptococcosis / Q000175:diagnosis / Q000473:pathology / Q000662:veterinary*; D003455:Cryptococcus neoformans; D003881:Dermatomycoses / Q000175:diagnosis / Q000473:pathology / Q000662:veterinary*; D005260:Female; D008297:Male; D046529:Microscopy, Electron, Transmission / Q000662:veterinary; D016133:Polymerase Chain Reaction / Q000662:veterinary; D012867:Skin / Q000382:microbiology / Q000473:pathology