Cancellous

(Anat.) Cellular. Cancer, ( kan's er ,) n. [Lat. cancer; A. S. cancre; formed from Gr. karkinos , a crab; Sansk. kark a , a crab.] ( Zool . ) A genus of decapodous short-tailed crustaceæ , family Cyclo me top a. (See BRACHYURA.) Linnæus arranged all the crustaceæ belonging to the Decapod a Brachyura, under the general name of cancer. Recent zoologists have restricted the genus within narrow limits, so as to contain only a few species. The common large edible crab, C. pagurus (Fig. 403), is the best known of these, though even this is removed by some to a separate genus, Platycarcinus . The carapace is large, rounded in front, narrow posteriorly, and the dorsal surface is granulated. Its color is reddish-brown, but the hands or claws are smooth and black. Of all the short-tailed crustaceæ, the crab is the most esteemed as an article of food, and the fishery constitutes an important trade on many parts of the coast. Their food consists of dead animal matter. The females are impregnated almost immediately after shedding their shell. The spawn is carried by them for a considerable time, and deposited at intervals during the spring and summer. When the young are first hatched, they are very unlike the parent, and were till lately considered as a distinct genus, and described under the name of Zoea . Several species of Zoea have been enumerated, which are either the young of different species of C., or only different stages of growth of these young crabs. (Astron.) The Crab, the fourth sign of the Zodiac which the sun enters on June 21st, when he reaches his greatest northern declination. The first point of C. is 90o distant from the first point of Aries, and is called the Sum mer Solstice. The parallel circle through this point is called the Trop ic of Cancer. The C. contains 83 stars, of which one of the 3d magnitude, Acubens . ( Med .) A peculiarly malignant and dangerous disease, so called because the ancients believed that the yellow and discolored veins and lines leading from the seat of the disease bore some resemblance to the crab, but profe ionally known as carcinoma. C., to use the popular name, is divided into two forms or stages- scirrhous , or occult, and ulcerated , or open cancer; the first being the primary stage, when the disease consists merely of a hard, painful tumor or swelling; the second, that advanced condition when the skin, having become involved, is in a state of open ulceration, discharging from its ulcerous ma a thin, irritating, and fœtid discharge. Of all the diseases that fall to the care of the surgeon, cancer is the most distre ing to witne , and most hopele to attend, for all parts of the body are liable to its inroads; though the organs most frequently attacked are the breasts of females, the glands generally, the womb, lips, tongue, eyes, nose, tonsils, and the skin. The lower lip in men, and the mammæ in women, are, however, the parts most frequently invaded by the disease. - Cancer seldom occurs under twenty-five years of age, the most general period for its attack being from fifty to sixty. A peculiarity of this disease is, that the younger the patient when attacked, the more rapid is the progre of the disease. Thus, in youth, cancer will frequently run its career in a few weeks, while in age it will continue in a state of torpidity for years. The tumor at first is small, hard, indolent, and nearly insensible, with little or no discoloration of the surrounding skin. It remains in this state for a longer or shorter period, but at length it pa es into a more active condition; - the tumor increases in size, the skin changes to a livid or red appearance, and pain begins to be felt in it. The pain, which is of a shooting or lancinating nature, is at first slight, and occurs at considerable intervals; but it increases by degrees, and the intervals diminish until it becomes almost constant. The cutaneous veins become turgid, and the surface of the tumor presents to the feel a knotty, uneven surface. Sometimes the skin never actually breaks, but usually, after a longer or shorter period, the tumor ulcerates and becomes an open sore. The discharge is of a thin, fœtid, acrid nature, which corrodes the surrounding parts. The sore presents thick jagged edges and a soft centre, eaten, as it were, into irregular cells. The shooting pains are now much increased, and are of a very violent nature. The disease pursues its onward course; sometimes it seems as if it had exhausted itself, and was allowing nature to work a cure by the formation of new flesh; but this is merely a delusion, for it soon recommences its destructive course, and at length, it may be after years, it seizes upon some vital organ, or the patient sinks exhausted by the pain and continued drain upon his system. Of the cause, nature, or treatment of this terrible disease little is, unfortunately, known. By some it is regarded as constitutional, by others as local; some maintain that it is hereditary, others that it may be transmitted by inoculation. So far as may be judged from the conflicting evidence on these points, there does seem, in general, to be a certain constitutional predisposition to this disease. The evidence is against its being transmitted by inoculation. If C. be at any period merely a local disease, it can only be in its earliest stage, for in a short time the whole system seems to be infected with it; and hence it is that after a time the extirpation of the original tumor so often fails in effecting a complete cure. Though C. is, unfortunately, by no means uncommon, it is not all, nor even the majority of tumors that bear a general resemblance to it, that are cancerous; in fact, it is often with the greatest difficulty that the cancerous or non-cancerous nature of a tumor can be determined; the presumption always is, in the case of a tumor getting well, that it was not C.; hence the great importance, in every suspicious case, of having recourse to a skilful surgeon. The only hope of a cure in C. is by extirpating the tumor in its earliest stages; and even this, after all, frequently affords but a temporary relief. According to Mr. Paget (Lectures on Surgical Pathology ), the average duration of life after the appearance of C. is 49 months. In 49 cases, in which the C. was once removed by operation, the average duration of life was somewhat more than 49 months; and hence he concludes that the average duration of life is not materially affected by the removal of the local disease, but adds, that it is probable that the progre of the more rapid cases is retarded by the operation. Sometimes, in place of the knife, escharotics, as chloride of zinc, are had recourse to, but with no better succe . Though a cure may not be expected, much good may be effected by means of palliatives; the patient is to be sustained by good nourishing diet, but all stimulants are to be avoided, and everything that would tend to increase the activity of the disease. The state of the general health is to be carefully attended to, and both mind and body kept as free from excitement as po ible. In the local treatment of this disease, sedatives, as hemlock, henbane, and opium, are to be had recourse to in order to allay the pain. Among the lower animals this disease is not of unfrequent occurrence, the animals most liable to its attack being the dog and cat. Can'cerate, v. i. [Lat. cancer are.] To become cancerous; to grow into a cancer. "But striking his fist upon the point of a nail in the wall, his hand cancerated." - L'Estrange.