Characteristic myxomas are mucoid tumors which chiefly originate from the mucous membrane and are especially to be found within the nasal passages and uteri of cattle. They can reach a size of three fists, are smooth or velvetlike, or may be lobulated, broad at the base, and consist of a glassy-looking mass of connective tissue, which usually shows a distinctive yellowish color. Being homogeneous and elastic, the moist, jellylike tissue composing the tumor may be easily destroyed or crushed. When cut through, these tumors soon collapse from the loss of their fluids. They sometimes inclose elliptical cavities filled with slimy, gelatinous masses.
Treatment.—Extirpation.
SARCOMA.
This is a malignant tumor after the type of embryonal tissue, and consists of several varieties, such as the round cell, spindle cell, giant cell, alveolar, and melanosarcoma. They grow by preference in connective tissue and are quite vascular. Sarcomas appear either as single or multiple nodules, varying in size from a hempseed to a hazelnut, or else as a moderate number of tumors of the size of hen eggs. Their surface, at first smooth, later becomes lumpy and tuberous from internal degeneration. Secondary nodules may appear near the primary tumor. The outer skin is not involved so soon as in cancer, nor does ulceration follow so rapidly. Sarcoma is about the most frequent and dangerous tumor that is found in cattle. It occurs in young animals, and is found on the serous membranes, in the glandular organs, and on the outer skin, especially of the neck and shoulders—in fact, in nearly every tissue and in almost every part of the body. This tumor is often found in places exposed to traumatisms and at seats of scars, or of irritations from pressure and inflammation.
Treatment.—Treatment should consist in early and complete removal by the knife, including one-half or three-quarters of an inch of the sound tissue adjoining the tumor. If there is a possibility that sarcomatous tissue still remains, either cauterize the wound with a hot iron or powder the walls of the cavity with arsenious acid.
CANCER (CARCINOMA).
Cancers are tumors of epithelial tissues and are malignant. There are several varieties of cancers, such as hard, soft, and colloid, but only those growing on the surface will be mentioned here. These malignant tumors of the superficial organs develop primarily from the epidermis or from the glands of the skin. They appear secondarily as spreading infections from milk glands, thyroids, anal glands, or as embolisms. In such cases their sole character depends wholly upon the kind of cancer from which they have sprung. The infiltrating cancer begins as an elevation of the skin, which progresses until it becomes rough and nodular. The surface later becomes attacked, and an ulcer results whose edges are outlined by a hard, firm zone.
The ulcerations may remain limited by cicatricial tissue, but it is more likely that the infiltration and destruction of tissue will spread out wider and deeper until a rodent ulcer (so called) is formed. One of the most frequent sites of cancer in cattle is in the eye, where they are called fungus hematodes, but they also occur on the skin, on the genitals, in the stomach, and within the organs.
Fungus hematodes.—This starts at the inner corner of the eye as a papillary elevation or as small nodules which become fused. They grow larger and become papillomatous, with superficial ulcerations and a tendency toward hemorrhage. In some cases the eye is displaced by the growing tumor or is attacked by the cancer cells and entirely destroyed.
Cancerous growths upon the external genitals and the anus usually present a rough, irregular surface from which there is a constant sloughing of decomposed tissue accompanied with a penetrating disagreeable odor.