Neoplastic and Nonneoplastic Tumors

CHAPTER | 14 Neoplastic and Nonneoplastic Tumors





Intracutaneous Cornifying Epithelioma (keratoacanthoma, infundibular keratinizing acanthoma)






Feline Solar Dermatosis






Treatment and Prognosis










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FIGURE 14-4 Feline Solar Dermatosis.


Same cat as in Figure 14-3. The crusts have been removed, revealing the erythematous papular lesions.







Canine Solar Dermatosis






Treatment and Prognosis





















Squamous Cell Carcinoma



Features


Squamous cell carcinoma is a malignant neoplasm of keratinocytes that accounts for 15% of cutaneous tumors in cats and 5% of cutaneous tumors in dogs. It most often occurs in thinly haired, nonpigmented, sun-damaged skin and may be preceded by actinic (solar) keratosis. Recently, papillomavirus infection has been implicated in tumor development in dogs, as papillomavirus antigen can be demonstrated in up to 50% of canine squamous cell carcinomas. Squamous cell carcinoma is common in dogs, with highest incidence in older dogs. Sunlight-induced tumors on the flank and ventrum occur most commonly in lightly pigmented dog breeds such as Dalmatians, Beagles, Whippets, and White English Bull terriers. The condition is common in cats, with highest incidence reported in older white cats. The incidence of solar-induced squamous cell carcinoma is highest in geographic areas with intense sunlight.






Treatment and Prognosis


















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FIGURE 14-30 Squamous Cell Carcinoma.


Close-up of the dog in Figure 14-29. This raised tumor has a deep ulcer, with tissue destruction forming a central crater.




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FIGURE 14-33 Squamous Cell Carcinoma.


Same cat as in Figure 14-32. The tumor has been ablated, leaving a focal area of ulceration.


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FIGURE 14-34 Squamous Cell Carcinoma.


Same cat as in Figure 14-32. Three weeks after treatment, the focal area has healed and the hair is regrowing. Early detection and therapeutic intervention provide better cosmetic outcomes.



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FIGURE 14-36 Squamous Cell Carcinoma.


Same cat as in Figure 14-35. The tumors were ablated with a carbon dioxide (CO2) laser and were allowed to heal. Early detection and therapeutic intervention provide better cosmetic outcomes.



Bowen’s Disease/Multifocal Squamous Cell Carcinoma In Situ





Treatment and Prognosis
















Basal Cell Tumor/Carcinoma






Hair Follicle Tumors



Features


Hair follicle tumors appear usually as benign neoplasms of germinal hair follicle cells that are classified according to the direction of adnexal differentiation. They are common in dogs and rare in cats. Trichoepitheliomas and pilomatrixomas are the most common follicular tumors.











Sebaceous Gland Tumors





Treatment and Prognosis
















Sep 10, 2016 | Posted by in SMALL ANIMAL | Comments Off on Neoplastic and Nonneoplastic Tumors

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