A tumour is a swelling or new production, and not a part of the original composition of the body. Blood may have been effused, and the coagulated part, becoming organised, is increased in size by deposits from the vessels which enter it; or perhaps the blood, the coloured part of it at all events, is taken up and lymph is deposited, which, if not also removed, “undergoes further changes of a secondary nature, and remains a parasite or new structure.” Its structure and growth are modified according to the action which its own vessels assume, independently of the surrounding vascular system. The bloodvessels may enter this new growth by a narrow pedicle; or it may be of such a form as to present an extensive surface, by which it communicates with the surrounding parts, receiving vascular ramifications from them. As the growth of the tumour proceeds, the surrounding parts yield, are condensed, and form an envelope for the new formation; the neighbouring bloodvessels are excited to a greater degree of action, and more blood is poured into the vessels of the tumour; the action of these in turn is very vigorous, and the increase of the new growth is more and more rapid. They become, it would appear, dilated and tortuous. Morbid enlargement, or rather new productions, often attain an enormous size; some have weighed, when recent, upwards of 60 or 70 lbs. Tumours differ much in structure; and though their general appearance may not be dissimilar, one will scarcely be found exactly resembling another. In many cases, the external appearance proves no certain index of the nature of the tumour; sometimes, however, its feel and general external character lead the experienced surgeon to form a correct estimate of its internal structure. It is impossible, by any process of reasoning, to account for the different actions which these growths possess; and even minute anatomical investigation, either of healthy or morbid structures, has not as yet thrown much light upon the subject.
Tumours are divided into Solid and Encysted. The solid are generally enveloped by a dense cellular sheath of the surrounding cellular substance, yielding and becoming condensed in proportion as the tumour increases in size; this covering appears as a barrier between the healthy and diseased parts, shutting out the latter, as much as possible, from connection with the rest of the body, and preventing the former from participating in the injurious tendencies of the latter. Some tumours have no such limit, but extend in the direction where there is the least resistance, hold a free intercourse with the surrounding parts, and impart to them their morbid disposition and action; others are limited in their situation and communications, but prove dangerous or annoying from their bulk. Some grow rapidly, and prove troublesome in a few weeks or months; others remain without much increase for years, and produce little or no inconvenience. Occasionally tumours partly resemble the texture in which they grow; those of a fatty nature are frequently found to have their nidus in the adipose tissue; cartilaginous tumours project from the surfaces of bones or of a joint, are subsequently detached, and lie loose in its cavity; growths of a cellular structure internally, and invested by an apparently mucous lining, protrude from the surface of mucous membranes. Others differ, not only from the texture in which they are situated, and from which they derive their nutritive vessels, but also from every other part of the healthy structure. In one instance, a congenital tumour was found to be composed of an aggregation of numerous materials, many of them resembling the healthy textures of the body. But again, tumours are constantly met with, composed of matter which in no respect resembles any of the natural tissues of the body: those are what have been called heterologous formations.
The simple tumour is mere enlargement of a part, from the infiltration of solid matter deposited by its bloodvessels. There can be little doubt that the action which lays the foundation of such enlargement is inflammatory: in consequence of inflammation of the tissue, lymph is effused into the cellular substance during the progress of the incited action; and after it has subsided, the dilated and debilitated vessels probably do not regain their condition, as to size and vigour, but remain somewhat dilated, and continue to free themselves from portions of their contents; thus the cellular tissue is opened out in proportion as the infiltration advances, and the process may be occasionally accelerated by fresh attacks of subacute inflammatory action. The patient at first feels pain, heat, &c., as in an inflammatory tumour; these afterwards abate, and ultimately go off entirely; and during the increase of the swelling, little or no pain is experienced, unless when these subacute inflammatory attacks supervene, and then it is but slight; or unless the enlargement be resisted by an unyielding structure, and then it is acute and troublesome. The size and rapidity of increase in such tumours will vary according to circumstances; the vessels of the part soon regain their size and action, either by the efforts of nature or of art, so that the tumour will have attained no great size, and be stationary in its progress, being denied the materials necessary for its increase. If the morbid action be thus stopped, the absorbents will remove the newly-formed matter, and restore the parts to their healthy condition. But when the deposition proceeds in a superior ratio to absorption, the new matter becomes organised, and by means of its own vessels, secretes a substance similar to itself, whereby the increase of the tumour becomes more rapid, and the new structure may attain an enormous bulk. Thus the tumour is formed, not merely by dilatation of capillary vessels, and extension of its original tissue, but by the formation of new matter, which, becoming organised, assumes a secreting power. At first the former circumstance is the chief cause of the enlargement; but after the latter process has existed for some time, the tumour loses much of its resemblance to the primary tissue, assumes a more dense structure and a different action, and therefore cannot be designated a simple enlargement.
This species of tumour, or rather this enlargement which precedes the formation of a tumour, is chiefly met with in the cellular and glandular structures. Sometimes it is described under the term of œdema solidum. In the scrotum, where the cellular tissue is remarkably loose and extensile, such tumours attain a very large size. They are found in this country, though more frequently in warm climates. I removed one from this situation successfully, which weighed upwards of 44-1/2 lbs.; it had been of twelve years’ duration, and caused much inconvenience to the patient. It is sketched in the Practical Surgery, p. 341. It occurs in the mamma, apparently in consequence of suppression of the menstrual discharge; the gland becomes enlarged, there is no pain in the tumour, and it feels soft and doughy. When the subcutaneous cellular tissue is the seat of the disease, the tumour is often of considerable extent, but rarely forms a great protuberance. It sometimes is situated in the coverings of the nose, which, as they become enlarged, lose their natural colour, and assume a purple hue; the mucous follicles also are often much enlarged, and occasionally emit a profuse discharge of their secretions. It can be readily understood that in this situation the tumour is a source of much annoyance, from its partially obstructing respiration, and even vision, interfering with the functions of the parts and the comfort of the patient.
It has been already observed, that when simple enlargement exists for some time the structure changes. It becomes more dense, and assumes a peculiar action, independent of that of the surrounding parts. It has a harder and more firm feel, and all traces of the texture in which it was formed are destroyed. It may be considered as the next in order to the one already mentioned, both as to the simplicity of its structure and action; but in consequence of its action being independent of those of the neighbouring parts, and liable to change from even slight causes, it is very apt to degenerate into those tumours which are more complex and injurious.
ADIPOSE TUMOURS.
Another species of tumour seems to be composed almost entirely of fatty matter insinuated amongst extended and delicate cellular substance, and has been therefore termed adipose. It is surrounded by a cyst of dense cellular tissue, and to this it loosely adheres; its bloodvessels are few, and it is of an inactive and innocuous character. It is generally lobulated, and often attains a large size. It is not only irregularly prominent on its outer surface, but in its whole circumference, and its lobuli often insinuate themselves to a great depth amongst nerves, bloodvessels, and other important parts; owing to this circumstance they frequently prove a source of the greatest inconvenience from their bulk, for of themselves they are neither hurtful, nor possess any disposition to involve those parts with which they are in contact. This tumour is found only in the cellular and adipose tissues. From its loose connection with its envelope, it admits of ready removal by operation. A tumour of this kind is here represented, which, but for this circumstance, owing to its awkward situation under the tongue, could not by any possibility have been extirpated. It is fully larger
than an orange, and had caused very great suffering. It is not so much lobulated as fatty tumours generally are. The adhesions of adipose tumours are, however, rendered firm and more numerous by pressure or external stimulants—in fact, by whatever induces inflammatory action in its substance or in its surrounding connections; and from this cause the extraction is often rendered exceedingly difficult. The skin becomes thickened and of a red hue, and the tumour itself is much more vascular. From this cause it is apt to assume a new mode of action, and to change in structure and in character, invariably for the worse. I have removed a few tumours, originally of this benign species, but which had apparently degenerated and assumed a malignant action. In one, distinct indurated bands radiating from a central mass of the same kind, are discernible. In two others, as a consequence of pressure, condensation and ultimate softening had occurred. The largest alluded to was removed from betwixt the shoulders of a soldier, and had borne the pressure of his knapsack for eight or ten years. It was attached by a thickish neck, presented the common lobulated appearance of adipose sarcoma; but its external surface, its feel, and section, were very different.
The patient does not complain of any pain or uneasiness in the tumour, unless inflammation be excited in it; then the pain and other symptoms are such as attend incited action, and the sensations which are afterwards experienced vary according to the character which the tumour assumes. Certain changes may occur in its texture, though not in its general character or disposition; thus osseous or earthy matter is occasionally deposited in some part of the tumour, while the surrounding adipose substance retains its appearance and density. Suppuration, it is said, has followed inflammatory action, excited in an adipose sarcoma.