Equine congenital papilloma: pathological findings and results of papillomavirus immunohistochemistry in five cases.

TitleEquine congenital papilloma: pathological findings and results of papillomavirus immunohistochemistry in five cases.
Publication TypeJournal Article
Year of Publication2004
AuthorsWhite KS, Fuji RN, Valentine BA, Bildfell RJ
JournalVeterinary dermatology
Volume15
Issue4
Pagination240-4
Date Published2004 Aug
ISSN0959-4493
KeywordsAnimals, Animals, Newborn, Female, Horse Diseases, Horses, Immunohistochemistry, Male, New York, Papilloma, Records as Topic, Retrospective Studies, Skin Neoplasms
Abstract

Abstract Congenital cutaneous papillomas were identified in five foals. Age at diagnosis ranged from 305 days' gestation to 2 days of age. Breeds were thoroughbred (2), standard-bred (1), warmblood (1) and paint (1). Two were female, one was male and the gender of two cases was not specified. Masses were pedunculated with a roughened, wart-like (verrucous) or a smoother, cauliflower-like surface. Masses occurred as single lesions on the forelimb, lip and face, or as multiple lesions on the trunk. Histological features included relatively uniform epidermal papillary hyperplasia with variable melanin pigment within basal layers and vacuolization of keratinocytes in all layers, but with no evidence of nuclear or cytoplasmic changes (koilocytes) characteristic of viral infection. One case showed epidermal proliferation with proliferation of pilosebaceous units. Results of immunohistochemical studies for the detection of papillomavirus antigens were negative in all cases. These results suggest that equine congenital papilloma may be a hamartomatous lesion (epidermal nevus) and not a viral-induced growth.

Alternate JournalVet. Dermatol.