Gliomata. — Glioma and ganglionar neuroglioma, though of epithelial origin, are classified among the connective-tis sue tumors. In one of my cases at Elwyn, of a cerebral glioma, careful inspection revealed only a local swelling, flattening, increase in size of the convolutions, and slight difference in color, and the tumor was distinguished from the healthy cere bral structures with the greatest diffi culty. Microscopically gliomata are com posed of neuroglia, the cells giving off delicate fibres, which interlace the one with the other, the cells, which assume a large variety of shapes, having one or more nuclei. If the amount of blood contained in the dilated blood-vessels is large, they have a reddish color and softer consistency. Ganglionar neurogliomata are made up of hypertrophic neuroglia, ganglionar cells, and nerve-fibres. They form striking pictures under the micro scope, and must be looked upon as due to developmental errors occurring in ex tra-uterine life.
Sarcomata.—The cells in sarcomata re semble those seen in embryonal tissue, and greatly predominate, both in number and relatively in size, over the intercel lular substance. They start either hi those situations where we normally have connective tissue; in tumors of con nective-tissue origin, such as fibroma, chondroma, etc.; in the uterine dccidua, or in dermoids. Sarcomata are rare in the liver, intestinal tract, uterus, and lungs. Degenerative changes are com mon. We may recognize three groups: I. Those composed of conglomerations of ordinary cells, not arranged in any special order or possessing any peculiar characteristics. 2. The cells are so ar ranged as to resemble cancerous tumors. 3. The cells, matrix, or vessels possess certain inherent characteristics which give rise to visible peculiarities. In the first group belong the small-celled and large-celled sarcomata, lymphosarcoma, small spindle-celled and large spindle celled sarcomata, and polymorphous forms, such as the oat-seed-like variety of Hamilton. Giant-celled sarcomata are classed as a separate genus under mye lomata. The second group consists of the alveolar sarcoma, the tubular sar coma, and the endotheliomata. The lat ter tumors are found in the coverings of the brain, pleura, periosteum, pericar dium, breast, and skin. They combine at times with angiomata. in the third group we have pigmented cells, melano sarcoma, and chloroma. In psammona there is a deposit of sand.
Lanz (Dent. med. Woch., No. 20, '99) has shown that the introduction of mel anosarcomatous tissue into the spleen of a guinea-pig is attended in six weeks with the production of pigmented cells in the skin and various other organs of the animal experimented upon.
Myelomata. — Myelomata arise from the red marrow of cancellous bone, and are especially liable to occur in those situations and periods of life where it is present in the largest quantities. Ow ing to its great vascularity, its cut sur face looks like fresh liver. Microscop ically the giant cells predominate, though round and spindle cells may be present in considerable numbers. The tibia is the bone most frequently affected, usu ally in its upper position, while the radius is attacked but one-fifth as often. Of the bones of the head, the jaws alone are af fected. The diseasc usually occurs be fore the 25th year, and metastasis is rare. The neoplasms sometimes weigh from 30 to 40 pounds, and, though rare, form such striking specimens that few mu seums are without a goodly number of them upon their shelves. Thorough enucleation or high amputation will often result in permanent cure.
Myomata.—Unstriped muscular fibres go to make up the tissue of a myoma, and the tumor is then called leiomyoma by those who designate tumors composed of striped muscular tissue as rhabdo myomata. These tumors are, however, better classed among the sarcomata. They are widely distributed throughout the body, and are usually combined with fibrous tissue. In the uterus they may be situated beneath the peritoneum within the uterine wall, and beneath the mucous membrane, and are called, re spectively, subserous, intramural, and submucous myomata. They occur also in the adnexa and ligaments around the uterus, in the intestinal tract, scrotum, skin, bladder, and prostate. Microscop ically the fascicular bands of muscular tissue are cut at all angles, and give a most varied appearance to the field, re sembling here a spindle-celled sarcoma and there the cells of a fibroma. They undergo mucoid degeneration, fatty met amorphosis, telangiectatic changes, cal cification, septic infection, etc. Death may ensue through haemorrhage, me chanical effects, pregnancy, or peritonitis. To the touch they feel like a pregnant uterus. A gynmcologist once sent me a specimen which he had removed at an operation, and said he waited until he was alone before venturing to see whether or not he had made an error of diagnosis. At the menopause they usu ally cease growing, and for this reason oophorectomy is often practiced with benefit.