Tumours Of The Skin And Subcutis Notes

Tumours of the Skin and Subcutis The most frequently diagnosed neoplastic disorders in domestic animals. General CS - nodular or papular, localized or generalized alopecic plaques, erythematous and pigmented patches and plaques, wheals, or nonhealing ulcers. The variability in clinical presentation can make distinguishing a neoplasm from an inflammatory disease difficult Dx - histopathology is generally required. Cytologic evaluation can also be useful. Skin tumours are the most common tumour in dogs and the second most common in cats. Most types are more common in older animals, but Histiocytomas, Viral Papillomas and Transmissible Venereal Tumours are more common in young dogs. Basset hounds, boxers, bull bastiffs, scottish terriers and weimeraners are at increased risk of development on skin tumours. Most cutaneous masses are benign in dogs, but malignant in cats. Tumour Definition Appearance Treatment Basal Cell Tumours Develop from the basal cells of the epidermis, and may be benign or malignant. One of the more common skin tumours of cats. Firm, solid or cystic, possibly pedunculated masses. In cats the mass may be found on the head, truck or limbs, in dogs masses are more commonly found on the head, neck and shoulders. The mass is often pigmented and may be ulcerated If benign, nothing. If carcinomas then exision or radiation therapy. Ceruminous Gland Adenomas or Adenocarcinomas Develop from the ceruminous glands in the external ear canal. The most common tumour of the external ear and more common in cats. Brown, pedunculated mass that produces cerumen and is located near the tympanic membrane. Adenocarcinomas look similar but are more invasive. Excision, TECA or radiation. Epidermal Inclusion Cysts Secondary to obstruction of a hair follicle contains thick, white to brown exudate. Not necessary but excision id causing a problem. Dermoid Cysts Similar to epidermal inclusion cysts but are the result of a developmental abnormality and may contain hair, sebum, keratinised material and fluid. Histiocytomas (Button Tumours) Benign tumours that develop from monocytemacrophage cells in the skkin. Most common in young dogs Usually appear as round, red/pink, alopetic nodules Not needed as usually regress in 1 2 months, surgical excision if causing a problem. Keratoacanthomas (Intracutaneous Cornifying Epitheliomas) Benign tumours of young dogs that develop from the epithelium in between the hair follicles. Only clinical sign is the presence of a soft to firm mass or nodule with a pore on the surface. The mass often contains a thick paste like material. ** In WikiVet Quiz - good picture. Not necessary but excision id causing a problem. Cutaneous Lymphosarcoma Dogs and rare in cats. Mean age is 8 - 10. Lymphomas in cats tend to be in FeLV +ve animals, but cutaneous lymphosarcoma cats are usually -ve Lesions appear as papules, nodules, tumours, erythematous plaques, cruts, ulcers and alopecia. Pruritus may be present. Diagnosis is based on skin biopsy Not necessary but excision id causing a problem. 

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