Terminology.—The principle of naming tumors is quite simple. The Greek word "oma" (plural "omata") means tumor. This word "oma" is added to the stem of the word ordinarily used to designate the kind of tissue of which the tumor is composed. Thus a tumor formed after the type of fibrous tissue is a fibroma. The only exception to this is in the naming of the two large classes of malignant neoplasms. There the names were formed from the fleshlike appearance of the one and the crablike proliferations of the other—namely, Sarcoma (sarks=flesh), carcinoma (karkinos=crab).
Diagnosis.—In the diagnosis of tumors note is taken of (1) clinical history and (2) examination of the tumor.
(1) Clinical history.—Circumstances connected with the origin of the tumor and its rapidity of growth may point to an inflammatory swelling rather than a tumor. The location of the tumor at its commencement is important, as, for instance, in diagnosing between lipoma and carcinoma, the former being more or less movable under the skin, while a carcinoma develops in the skin. While tenderness on pressure may be caused by compression of a sensitive nerve by a tumor or by tumors of the nerve or nerve sheaths, as a rule this symptom is indicative of inflammatory swelling rather than of the existence of a tumor.
(2) Direct examination of the tumor.—In the application of this diagnosis the trained observer will note color, size, shape, and surface structure, transmission of light, movableness, consistence, resistance, pulsation, and crepitation. Percussion, auscultation, and exploration are also available methods. Finally, microscopic examination of the growing portions of the tumor by a pathologist will be found most satisfactory.
GENERAL TREATMENT OF TUMORS.
For benign tumors treatment is required only when it damages the animal's value or when merely for sake of appearance. When it is possible, the removal of the tumor by an operation is indicated. If the tumor has a small, constricted base, remove by torsion, ligation, or with an écraseur. Ligation following the incision of the skin with a knife avoids the pain of pressing on the sensitive nerves of the skin and is suitable for tumors of broad base and small bodies. A firing iron, such as is used in line or feather firing, may also be used in removing tumors with small attachments. This not only stops the bleeding but forms a firm scab, under which healing may occur rapidly. Those tumors that can not be removed by the above methods may be treated with caustics or acids, such as sulphuric acid, hydrochloric acid, caustic potash, arsenic, silver nitrate, or chromic acid, but it is difficult to limit the action of these drugs. The injection, into the tumor, of such chemicals as anilin dyes, alcohol, acetic acid, citric acid, or ergotin, is of doubtful value, as is also the injection of the germs of erysipelas—thought by some to be a specific. Certain specific tumors, such as actinomycosis and botryomycosis, may be successfully treated by the internal administration of potassium iodid, together with the injection into the tumor or the painting of its surface with either Lugol's solution or the tincture of iodin. The most reliable means of treating tumors is by extirpation with cutting instruments. Dissect the tumor from the surrounding tissue, ligating all the larger blood vessels, and tearing the tissues with the fingers rather than cutting with a knife. The bleeding may be stopped with a hot iron. The after treatment is the same as for any ordinary wound of similar size.
DESCRIPTION OF INDIVIDUAL TUMORS.
Although a full list of the tumors that may be found in bovines has been given above, there are a number that warrant a detailed description, and the following mention will be made of the most important of them: