Limits...
Pathology and Epidemiology of Ceruminous Gland Tumors among Endangered Santa Catalina Island Foxes (Urocyon littoralis catalinae) in the Channel Islands, USA.

Vickers TW, Clifford DL, Garcelon DK, King JL, Duncan CL, Gaffney PM, Boyce WM - PLoS ONE (2015)

Bottom Line: On SCA, otitis externa secondary to ear mite infection was highly correlated with ceruminous gland hyperplasia (CGH), and tumors were significantly associated with the severity of CGH, ceruminous gland dysplasia, and age group (older foxes).We propose a conceptual model for the formation of ceruminous gland tumors in foxes on SCA that is based on persistent, ubiquitous infection with ear mites, and an innate, over exuberant inflammatory and hyperplastic response of SCA foxes to these mites.Foxes on SCA are now opportunistically treated with acaricides in an attempt to reduce mite infections and the morbidity and mortality associated with this highly prevalent tumor.

View Article: PubMed Central - PubMed

Affiliation: Institute for Wildlife Studies, Arcata, California, United States of America.

ABSTRACT
In this study, we examined the prevalence, pathology, and epidemiology of tumors in free-ranging island foxes occurring on three islands in the California Channel Islands, USA. We found a remarkably high prevalence of ceruminous gland tumors in endangered foxes (Urocyon littoralis catalinae) occurring on Santa Catalina Island (SCA)--48.9% of the dead foxes examined from 2001-2008 had tumors in their ears, and tumors were found in 52.2% of randomly-selected mature (≥ 4 years) foxes captured in 2007-2008, representing one of the highest prevalences of tumors ever documented in a wildlife population. In contrast, no tumors were detected in foxes from San Nicolas Island or San Clemente Island, although ear mites (Otodectes cynotis), a predisposing factor for ceruminous gland tumors in dogs and cats, were highly prevalent on all three islands. On SCA, otitis externa secondary to ear mite infection was highly correlated with ceruminous gland hyperplasia (CGH), and tumors were significantly associated with the severity of CGH, ceruminous gland dysplasia, and age group (older foxes). We propose a conceptual model for the formation of ceruminous gland tumors in foxes on SCA that is based on persistent, ubiquitous infection with ear mites, and an innate, over exuberant inflammatory and hyperplastic response of SCA foxes to these mites. Foxes on SCA are now opportunistically treated with acaricides in an attempt to reduce mite infections and the morbidity and mortality associated with this highly prevalent tumor.

Show MeSH

Related in: MedlinePlus

Photo of hematoxylin and eosin—stained histopathology slide of ceruminous gland dysplasia in a Santa Catalina Island fox (main image scale bar = 200 μm, inset = 50μm).
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4664485&req=5

pone.0143211.g007: Photo of hematoxylin and eosin—stained histopathology slide of ceruminous gland dysplasia in a Santa Catalina Island fox (main image scale bar = 200 μm, inset = 50μm).

Mentions: Histologic examination of necropsy and biopsy specimens from foxes with gross proliferative lesions revealed a spectrum of microscopic changes, both among cases as well as within individuals. Neoplastic proliferative lesions included adenomas, and cystic and solid carcinomas (cystadenocarcinoma; Fig 5; adenocarcinomas; Fig 6). Affected foxes had various degrees of chronic otitis externa accompanied by marked hyperplasia and hyperkeratosis of the epidermis and multifocal ulceration. Mites, identified as Otodectes cynotis (U.S. National Parasite Collection number 093186.00), were present in a majority of both live (98%) and deceased (58.5%) foxes with otitis. All tumor cases had varying degrees of ceruminous gland hyperplasia, some with papillary projections into the glandular lumen. In the areas of florid hyperplasia, the epithelium piled up into multiple disorganized layers and formed small nests and acini without breaching the basement membrane (dysplasia; Fig 7). In some cases, hyperplastic epithelium formed polypoid projections into the ear canal with a concurrent chronic inflammatory infiltrate (inflammatory polyps).


Pathology and Epidemiology of Ceruminous Gland Tumors among Endangered Santa Catalina Island Foxes (Urocyon littoralis catalinae) in the Channel Islands, USA.

Vickers TW, Clifford DL, Garcelon DK, King JL, Duncan CL, Gaffney PM, Boyce WM - PLoS ONE (2015)

Photo of hematoxylin and eosin—stained histopathology slide of ceruminous gland dysplasia in a Santa Catalina Island fox (main image scale bar = 200 μm, inset = 50μm).
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4664485&req=5

pone.0143211.g007: Photo of hematoxylin and eosin—stained histopathology slide of ceruminous gland dysplasia in a Santa Catalina Island fox (main image scale bar = 200 μm, inset = 50μm).
Mentions: Histologic examination of necropsy and biopsy specimens from foxes with gross proliferative lesions revealed a spectrum of microscopic changes, both among cases as well as within individuals. Neoplastic proliferative lesions included adenomas, and cystic and solid carcinomas (cystadenocarcinoma; Fig 5; adenocarcinomas; Fig 6). Affected foxes had various degrees of chronic otitis externa accompanied by marked hyperplasia and hyperkeratosis of the epidermis and multifocal ulceration. Mites, identified as Otodectes cynotis (U.S. National Parasite Collection number 093186.00), were present in a majority of both live (98%) and deceased (58.5%) foxes with otitis. All tumor cases had varying degrees of ceruminous gland hyperplasia, some with papillary projections into the glandular lumen. In the areas of florid hyperplasia, the epithelium piled up into multiple disorganized layers and formed small nests and acini without breaching the basement membrane (dysplasia; Fig 7). In some cases, hyperplastic epithelium formed polypoid projections into the ear canal with a concurrent chronic inflammatory infiltrate (inflammatory polyps).

Bottom Line: On SCA, otitis externa secondary to ear mite infection was highly correlated with ceruminous gland hyperplasia (CGH), and tumors were significantly associated with the severity of CGH, ceruminous gland dysplasia, and age group (older foxes).We propose a conceptual model for the formation of ceruminous gland tumors in foxes on SCA that is based on persistent, ubiquitous infection with ear mites, and an innate, over exuberant inflammatory and hyperplastic response of SCA foxes to these mites.Foxes on SCA are now opportunistically treated with acaricides in an attempt to reduce mite infections and the morbidity and mortality associated with this highly prevalent tumor.

View Article: PubMed Central - PubMed

Affiliation: Institute for Wildlife Studies, Arcata, California, United States of America.

ABSTRACT
In this study, we examined the prevalence, pathology, and epidemiology of tumors in free-ranging island foxes occurring on three islands in the California Channel Islands, USA. We found a remarkably high prevalence of ceruminous gland tumors in endangered foxes (Urocyon littoralis catalinae) occurring on Santa Catalina Island (SCA)--48.9% of the dead foxes examined from 2001-2008 had tumors in their ears, and tumors were found in 52.2% of randomly-selected mature (≥ 4 years) foxes captured in 2007-2008, representing one of the highest prevalences of tumors ever documented in a wildlife population. In contrast, no tumors were detected in foxes from San Nicolas Island or San Clemente Island, although ear mites (Otodectes cynotis), a predisposing factor for ceruminous gland tumors in dogs and cats, were highly prevalent on all three islands. On SCA, otitis externa secondary to ear mite infection was highly correlated with ceruminous gland hyperplasia (CGH), and tumors were significantly associated with the severity of CGH, ceruminous gland dysplasia, and age group (older foxes). We propose a conceptual model for the formation of ceruminous gland tumors in foxes on SCA that is based on persistent, ubiquitous infection with ear mites, and an innate, over exuberant inflammatory and hyperplastic response of SCA foxes to these mites. Foxes on SCA are now opportunistically treated with acaricides in an attempt to reduce mite infections and the morbidity and mortality associated with this highly prevalent tumor.

Show MeSH
Related in: MedlinePlus