cutaneous Tumors ll (classification)

Frequent tumors of skin but:

Melanomas
Frequent Neoplasia in the rare dog and in the cat. He is neoplasia of the melanocitos (cells that are in epidermis). Its appearance partly must to hereditary factors and to the solar exhibition not as much cumulative but rather the occasional intense exhibition. Normally solitary of face location, trunk, escroto and legs in the dog, and the head and auricular pavilion in cats species in which the majority is malignant.
In the dog those of oral, mucocutánea, digital location and escroto are malignant and of the rest approximately 50%. By biospsia (anatomopatológicamente) different categories are distinguished, although as characteristic special often a good correlation between comportamientodel cannot be established tumor and the microscopic characteristics (of the biopsy).

Cutaneous Papiloma:
Frequent in rare dog and in the cat. Benign Neoplasia with probable viral etiología. It can simple or multiple, pedunculado and be multilobulado. It responds to the treatment very well. Single in some cases it can have malignant transformation to carcinoma of escamosas cells.

Carcinoma of basal cells:
The cancer of basal cells is the type commonest of cancer of the skin not melanoma. Generally, one appears in areas of the skin that been have exposed to the sun. Often this cancer appears in form of a swelling with smooth appearance and nacarada, is very rare that they metastaticen (to scatter itself to other parts of the body).

Actinic Queratosis:
The actinic queratosis is a noncancerous upheaval of the skin but that in mascots can with time become cancer of basal cells or cancer of escamosas cells. It appears in the skin in form of escamosos and rough patches, of red or brown color, generally in the areas that have been exposed to under /l. (pavilions of ears, nose).

Carcinoma of escamosas cells:
Frequent in dog and cat. Common in white cats or dogs of white layer (Dalmatian), outer life or with nasal despigmentación associated to THEM and other despigmentantes diseases (nose of the Collie). The tumors of the cells escamosasse present/display in areas of the skin that been have exposed to the sun, often in the superior part of the nose, ends of the ears or zones despigmentadas with little hair, ej.zona inguinal. Normally solitary in the dog and diverse locations; in the cat frequently they appear in the face region and they can be proliferativos or ulcerativos. The chronic solar burn is pronounced like actinic dermatitis characterized by hiperemia, cutaneous thickening and descamación. This state is preneoplásico and if the exhibition continues, it evolves finally in months to years to the carcinoma in situ and to the invasive carcinoma. Generally, this cancer appears like a reddish and hard swelling. Sometimes the tumor can have a escamoso aspect, or can bleed or develop a scab.
The tumors of escamosas cells can be scattered to the lymphatic ganglia in the area (the lymphatic ganglia are small structures in form of frijol that are in all the body and whose function is to produce and to store cells that fight the infection).

Fibrosarcoma:
Frequent in dogs and cats. There are two different presentations in the feline species: Fibrosarcomas solitary in extremities and trunk, frequently ulcerados and invasive locally in cats and old dogs and of unknown etiología and fibrosarcomas of multicentric presentation in young cats of viral etiología by the virus of sarcoma feline mutant of the FeLV. These cats are positive to FeLV.

Lipoma:
Frequent in the dog and rare in the cat. Solitaires or manifold, frequently in thorax, abdomen and extremities of subcutaneous location and benign behavior.

Liposarcoma:
Solitaires, same location of lipoma but of malignant behavior and worse prognosis.

Mastocitoma:
Frequent in the dog and the cat of unknown etiología. Variable presentation and location. In the dog they appear in the trunk, perineal zone and extremities and in the cat in the head and neck with high variety in the presentation in form of ulcers, elevated plates, pápulas and small nodules, etc. Can cause sistémica affectation by the histamina liberation [gastritis by gastroduodenales ulcers] and serotonin (coagulopatía). They are neoplasias which they are possible to be tolerated of benign form (it frequents in cats) or vitiates (30% cases in dogs specially in digital, perineal location, escroto and prepucio).

Histiocitoma:
Also call tumor button, in the case of the solitaires with very good I foretell, within this group is histiocitoma fibrous malignant with a prognosis even reserved with treatment. The age average of the affected ones is of 8 in dogs and 7 years in cats. There is racial predisposition in the descendants of the English Bulldog and Bull to terrier English (by ej., Boxer and terrier of Boston); the Siamese also seems prearranged. Although the diagnosis is simple, the treatment and prognosis is controverted.

Cutaneous Linfosarcoma:
The exclusive affectation of the skin in linfoma is very rare as much in the dog as in the cat. The negative cats are always FeLV. The cutaneous manifestations are diverse and multifocal with or without sistémica affectation. Anatomopatológicamente distinguishes linfomas epiteliotrópicos (lymphocytes T) and nonepiteliotrópicos (lymphocytes B). The behavior in all the varieties is malignant.

Follicular cysts (BADLY CALLED SEBACEOUS):
Gerontes or certain races is very common in animals (to cocker spaniel, basset, ovejero German) and consists of a growth, invaginación and quística obstruction of epitelio escamoso of the piloso follicle. The queratina is accumulated along with cellular detritus and lipids, which denominates ?tallow? and it possibly gets to break itself, with liberation of the previous thing to dermis (fatty acids mainly) causing a reaction of type strange body, inflammation and pain. So that the injury recidive is not recommended to be extracted the capsule completely, not to open them and to drain them.