title: Adenomatous hyperplasia of the mucous glands in captive Archey's frogs (Leiopelma archeyi).
abstract: OBJECTIVE
  To describe the gross and light microscopic characteristics of skin lesions observed on the ventral skin of captive Archey's frogs (Leiopelma archeyi) between 2000 and 2012, and to investigate their occurrence, possible aetiology and association with survival.
  
  
  METHODS
  Postmortem skin samples were obtained for histological evaluation from 37 frogs, with and without skin lesions, that died while in captivity at Auckland Zoo between 2000 and 2012. Four frogs with skin lesions were biopsied under general anaesthesia and samples used for both light and transmission electron microscopy. The records of 94 frogs held at the University of Otago and Auckland Zoo between 2000-2012 were reviewed, which included some frogs recently collected from the wild. Information about the occurrence of skin lesions, and mortality associated with skin lesions was collated.
  
  
  RESULTS
  Grossly the skin lesions varied in appearance; most were circular, pale grey papules, which measured from <0.5-1.5 mm in diameter with no umbilication. The overlying epidermis was not fragile and there was no associated inflammation. Contents often appeared clear or semi-transparent. Lesions were located predominantly on ventral surfaces including trunk, thighs, lower legs and forearms, and gular region, but not on digits. The number ranged from single to multiple, often confluent lesions covering the entire ventral surface of the frog. Histologically the lesions consisted of enlarged proliferating mucous glands that expanded the dermis and elevated the epidermis. They were semi-organised, solid or occasionally cavitated acinar structures with central lumina which sometimes contained mucus. Nuclei showed moderate anisokaryosis and mitotic figures were uncommon. Transmission electron microscopy did not show any infectious agents. Between 2000 and 2012, skin lesions were recorded in 35/94 (37%) frogs. The size and location of skin lesions varied over time, with some resolving and sometimes reappearing. Skin lesions were not associated with an increased risk of death.
  
  
  CONCLUSIONS
  The skin lesions had the gross and microscopic characteristics of adenomatous hyperplasia of the dermal mucous glands.
  
  
  CONCLUSIONS
  The aetiology of this adenomatous hyperplasia is unknown, but factors associated with the captive environment are the most likely cause. This is the first description of adenomatous hyperplasia of the cutaneous mucous glands in amphibians.
authors.affiliation: a New Zealand Centre for Conservation Medicine , Auckland Zoological Park, Auckland , New Zealand.|b One Health Research Group, College of Public Health, Medical and Veterinary Sciences , James Cook University , Townsville , Queensland , Australia.
authors.forename: S D
authors.initials: SD
authors.lastname: Shaw
authors.affiliation: b One Health Research Group, College of Public Health, Medical and Veterinary Sciences , James Cook University , Townsville , Queensland , Australia.
authors.forename: L
authors.initials: L
authors.lastname: Berger
authors.affiliation: c Gribbles Veterinary Laboratories , Auckland , New Zealand.
authors.forename: C
authors.initials: C
authors.lastname: Harvey
authors.affiliation: d Wildbase Pathology, Institute of Veterinary, Animal and Biomedical Sciences , Massey University , Palmerston North , New Zealand.
authors.forename: M R
authors.initials: MR
authors.lastname: Alley
authors.affiliation: e Department of Zoology , University of Otago , Dunedin , New Zealand.
authors.forename: P J
authors.initials: PJ
authors.lastname: Bishop
authors.affiliation: b One Health Research Group, College of Public Health, Medical and Veterinary Sciences , James Cook University , Townsville , Queensland , Australia.
authors.forename: R
authors.initials: R
authors.lastname: Speare
mesh_terms: D000818:Animals; D001001:Anura; D006965:Hyperplasia / Q000473:pathology / Q000662:veterinary*; D012867:Skin / Q000648:ultrastructure; D012871:Skin Diseases / Q000401:mortality / Q000473:pathology / Q000662:veterinary*
keywords: Adenomatous hyperplasia; Archey’s frog; Leiopelma archeyi; amphibian; mucous gland