A malignant new growth made up of epithelial cells tending to infiltrate surrounding tissues and to give rise to metastases. A form of cancer, carcinoma makes up the majority of the cases of malignancy of the mammary gland, uterus, intestinal tract, skin and tongue.
- acinic cell c. — locally invasive salivary gland tumors of dogs, and rarely other species, composed of glandular epithelium in an acinar pattern.
- adenocystic c., adenoid cystic c. — carcinoma marked by cylinders or bands of hyaline or mucinous stroma separated or surrounded by nests or cords of small epithelial cells, occurring in the mammary and salivary glands, and mucous glands of the respiratory tract. Called also cylindroma.
- alveolar c. — alveolar adenocarcinoma.
- apocrine c. — see apocrine tumors.
- basal cell c. — an epithelial tumor of the skin that seldom metastasizes but has potential for local invasion and destruction. Common in dogs and cats.
- basosquamous c. — carcinoma that histologically exhibits both basal and squamous elements.
- bronchogenic c. — carcinoma of the lung, so called because it arises from the epithelium of the bronchial tree.
- cholangiocellular c. — primary carcinoma of the liver originating in bile duct cells.
- chorionic c. — choriocarcinoma.
- colloid c. — mucinous carcinoma.
- cylindrical cell c. — carcinoma in which the cells are cylindrical or nearly so.
- embryonal c. — a highly malignant primitive form of carcinoma, probably of germinal cell or teratomatous derivation, usually arising in a gonad.
- epidermoid c. — that in which the cells tend to differentiate in the same way as those of the epidermis; i.e. they tend to form prickle cells and undergo cornification.
- giant cell c. — carcinoma containing many giant cells.
- hepatocellular c. — primary carcinoma of the liver cells.
- Hürthle cell c. — see hürthle cell tumor.
- c. in situ — a neoplastic entity wherein the tumor cells have not invaded the basement membrane but are still confined to the epithelium of origin; popularly applied to such cells in the uterine cervix.
- large-cell c. — a bronchogenic tumor of undifferentiated (anaplastic) cells of large size.
- medullary c. — that composed mainly of epithelial elements with little or no stroma.
- mucinous c. — adenocarcinoma producing significant amounts of mucin.
- oat-cell c. — small-cell carcinoma.
- papillary c. — carcinoma in which there are papillary excrescences; called also papillocarcinoma.
- scirrhous c. — carcinoma with a hard structure owing to the formation of dense connective tissue in the stroma.
- c. simplex — an undifferentiated carcinoma.
- c. of skin — squamous cell carcinomas occur on the third eyelid, cornea or the eyelid of cattle and horses, on the penis and prepuce of horses, from the mucosa of the frontal sinus to invade the horn core of cattle (called also horn cancer), on the ears of sheep, on the vulva of ewes when the tail is docked too short. In goats the ears, udder, base of the horn and perineum are also susceptible sites. The tumors grow rapidly, show considerable invasiveness and often metastasize to local lymph nodes. In dogs and cats, squamous cell carcinomas are common, particularly on the face and pinnae of white cats. See also squamous cell carcinoma (below).
- small-cell c. — a radiosensitive tumor composed of clusters of small, oval, undifferentiated cells that have hyperchromatic nuclei and scant cytoplasm and are typically bronchogenic. Called also oat-cell carcinoma.
- spindle cell c. — squamous cell carcinoma marked by fusiform development or rapidly proliferating cells.
- stomach c. — squamous cell carcinomas occur in the stomach of the horse and the bovine rumen. The associated clinical syndrome in the horse is one of indigestion and weight loss. Metastasis occurs commonly. In cows there may be vagus indigestion or chronic tympany of the rumen.
- transitional cell c. — occurs mainly in the urinary bladder of older dogs. Several structural types may be observed: papillary, polypoid, fungoid or sessile. Metastasis to regional lymph nodes and lungs is possible.
- udder c. — occurs rarely in mares and doe goats.
