Cancer and sarcoma are classified as malignant diseases because of their tendency to infiltrate the surrounding tissue: infect the lymphatic glands and distant organs; and to recur after removal. These characteristics are in sharp contrast with those of innocent or benign tumors which do not, as a rule, infiltrate, infect lymphatic glands, or recur after complete removal, and which only prove fatal when they exist in the vicinity of vital organs. Investigations as to the cause of these malignant growths have not given us any idea as to their bacterial or pathological origin, and it still remains a question as to whether they are due to bacteria, parasites, spores, toxins, or are hereditary.

Sarcoma

Sarcoma of the rectum seems to be about as frequent as sarcoma in the small intestine, and is more often found in men than women. The disease is one of adult life but occurs in children more commonly than other malignant growths. There are several different varieties, recognized as the round cell, spindle cell, giant cell, alveolar, and mixed sarcomas. The round cell, spindle cell, and alveolar are types most frequently found in the rectum, although the other types have been recognized. Sarcoma of the rectum consists of embryonic connective tissue cells imbedded in the inter-cellular substance and varying in character. The cells are either renucleated, or if uni nucleated rarely possess a limiting membrane. The tumors contain very little fibrous tissue, being composed chiefly of embryonic cells.

Malignant Growths

The type or variety of the growth is manifested by the shape, size and the arrangement of the cells. The presence or absence of a fibrous tumor, the character of the cells and the inter cellular substance give the characteristic consistence of the tumor. When there is a preponderance of the fibrous elements the tumor is spoken of as a fibrous sarcoma. All sarcomas exhibit certain similar features in their growth. They are not encapsulated and exhibit peripheral growth. They invade the surrounding tissue by progression along the tissue spaces and absorb the per-existing tissue excepting the supporting framework around the blood vessels and capillaries. This last characteristic is a marked feature of sarcomas and is well illustrated by the muscularity of the growths. Sarcomas growths have certain characteristics dependent upon their histological formation. Hemorrhage within the tumor is apt to occur, and metastases along the blood stream are commonly observed, as a result of freed sarcomas tissue in the blood vessels or lymphatics. Extension through the blood vessels is more common than through the lymphatics, dependent upon the proclivity to extend along the blood vessels.

Melanoma sarcoma of the rectum occurs twice as frequently as the non-melanoma type. Melanoma carcinoma in the rectum occurs very seldom.

The disease originates in the sub mucosa and produces elevations into the lumen of the gut in the form of single or multiple, round or elliptical tumors. The mucous membrane is movable over the growth during the early stages. The growths are composed of a comparatively hard tissue, but not so hard as the cirrhosis cancer. In the polypeptide form they resemble the adenoid polyp, which are elastic, with a firm, hard center. The disease as seen in the rectum has a decided tendency toward ganglionic infection. The lymphatics are invaded much earlier than in a corresponding growth at other portions of the body. Metastasis is therefore very apt to preclude operative interference at a very much earlier period than with cancer.

Symptoms. The nearer the anal margin the greater will be the pain, but when located high up in the rectum the pain is almost nil. The mass is globular and smooth as a rule, and not tender. There is an obstruction to the bowel movements, simulating constipation, but is less marked than in cancer, and less apt to form a stricture and cause obstruction earlier. Sarcoma is often associated with a dilatation of the bowel above the growth which allows an accumulation of the fecal matter and impaction. Ulceration from sarcoma is very late in the disease while cachepot develops early. Metastasis occurs early when the growth is soft, but later if it is a hard variety. We may have a rectal cancer remaining as a local disease for a long while, making the operative procedure much more favorable for a radical cure, by comparison, because of the tendency to metastases occurring early in sarcoma. Patients complain of fullness in the rectum first, then as the disease advances, diarrhea sets in, with pus and mucus in the stools. Often medical advice is only sought on the appearance of blood.

An intestinal obstruction is formed by the tumor pressing into the lumen of the bowel, causing an imagination or a voluminous, and not by cicatrice stricture, as in circular carcinoma.

A history of an injury at the site of the growth may be elicited in either carcinoma or sarcoma of the rectum. Malignant diseases usually are accompanied by an irregular or moderate temperature.

Diagnosis. The disease is apt to be confused with carcinoma, adenoid and fibroid of the rectum. Carcinoma has no pedicab, being situated in the epithelial layer of the mucous membrane. Sarcoma is peculated and can be distinguished from adenoid in not having as long a pedicab, and being firmer; but less so than carcinoma. Its attachment to the anal tissue is positively and clearly limited by its abruptness. In adenoid, the divisions, softness and extent of the growth are distinguishable features. Sarcoma is a disease of adult life, although found in children. The absence of the char acharacteristic odor of broken down carcinomas tissue will aid in its diagnosis. Adenoid and illus growths have a tendency to irritate the bowel and produce copious diarrhea, especially when the growth is undergoing degeneration from its excessive growth. The diagnosis may be confirmed by examining pieces of the discharged tissue under the micro-scope.