(Dr. J. M"Watt"s case.)]
The term _lymphangio-sarcoma_ is applied when the cells of the tumour are derived from the endothelium of lymph s.p.a.ces and vessels. The _angio-sarcomas_ are those in which blood vessels form a prominent element in the structure of the tumour. They are sometimes derived from innocent angiomas, and they may be so vascular as to pulsate and on auscultation yield a blowing murmur like an aneurysm. The _glio-sarcoma_, _myxo-sarcoma_, _chondro-sarcoma_, and _myo-sarcoma_ are mixed forms which usually develop in pre-existing innocent tumours. The _osteo-sarcoma_ is characterised by the formation in the tumour of bone, the medullary s.p.a.ces being occupied by sarcomatous cells in place of marrow. The _osteoid sarcoma_ is characterised by the formation of a tissue resembling bone but deficient in lime salts, and the _petrifying sarcoma_ by the formation of calcified areas in the stroma. These varieties, although met with chiefly in the bones, may occur in soft tissues such as muscle, and in such organs as the mamma. The pigmented varieties include the _chloroma_, which is of a light-green colour, and the _melanotic sarcoma_, which is brown or black. The _psammoma_ is a sarcoma containing a material resembling sand; it is chiefly met with in the membranes of the brain. The _chordoma_ is a rare form of tumour originating from the remains of the notochord in the region of the spheno-occipital synchondrosis or in the sacro-coccygeal region.
_Diagnosis of Sarcoma._--A sarcoma is to be differentiated from an inflammatory swelling such as results from tubercle, actinomycosis, or syphilis, from an innocent tumour, and from a cancer. The points on which the diagnosis is founded are discussed with the different tissues and organs.
_Treatment._--The removal of the tumour by operation is the most reliable method of treatment; in order to be successful it must be undertaken before dissemination has taken place, and a considerable area of healthy tissue beyond the apparent margin of the growth must be removed, and in tumours near the surface of the body, the overlying skin also.
In order to prevent recurrence, a tube of _radium_, to which a silk thread is attached, is inserted into the s.p.a.ce from which the tumour was removed; the thread is brought out at the drain-opening, and at the end of a week or ten days the tube of radium is removed by pulling on the thread. Radium causes a reaction in the tissues attended with exudation from the vessels, for the escape of which provision must be made. If radium is not available, the affected area is repeatedly exposed to the action of the _X-rays_ as soon as the wound has healed. The employment of these measures has diminished to a remarkable degree the recurrence of sarcoma after operation.
It will readily be understood that the less thoroughly or radically the growth has been removed, the more do we depend upon radium or the X-rays for bringing about a permanent cure, and that in advanced cases of sarcoma and in cases in which, on account of their anatomical situation, removal by operation is necessarily incomplete, the prospect of cure is still more dependent on the use of radium or of the X-rays. Finally, there are cases in which removal by operation is impossible, the so-called _inoperable sarcoma_; a tube of radium, to which a silk thread is attached, is inserted into the substance of the tumour, either through an opening made by a large trocar, or, when necessary, by open dissection. A second tube of radium is placed upon the skin over the tumour and is secured there by a st.i.tch or by a strip of plaster, thus securing a cross-fire action of the radium rays, both from within and without, as this is found to be much more efficacious in destroying or inhibiting the cellular elements of the growth. The tubes of radium are left _in situ_ for from eight to fourteen days, according to the power of the radium employed, but are moved about every second day or so in order that every part of the tumour may be efficiently radiated. If the tumour shrinks in size after the use of radium and becomes operable, it should be removed before time is given it to resume its growth. It will depend upon the subsequent course of the disease, whether or not a second, or it may be even a third, application of radium will be required.
Where neither radium nor X-rays is available or applicable, recourse may be had to the injection of Coley"s fluid, a preparation containing the mixed toxins of the streptococcus of erysipelas and the bacillus prodigiosus; or of selenium.
EPITHELIAL TUMOURS
An excessive and erratic growth of epithelium is the essential and distinguishing feature of these tumours. The innocent forms are the papilloma and the adenoma; the malignant, the carcinoma or cancer.
#Papilloma.#--A papilloma is a tumour which projects from a cutaneous or mucous surface, and consists of a central axis of vascular fibrous tissue with a covering of epithelium resembling that of the surface from which the tumour grows. In the papillomas of the skin--commonly known as _warts_--the covering consists of epidermis; in those growing from mucous surfaces it consists of the epithelium covering the mucous membrane. When the surface epithelium projects as filiform processes, the tumour is called a _villous papilloma_, the best-known example of which is met with in the urinary bladder. Papillomatous growths are also met with in the larynx, in the ducts of the breast, and in the interior of certain cystic tumours of the breast and of the ovary.
Although papillomas are primarily innocent, they may become the starting-point of cancer, especially in persons past middle life and if the papilloma has been subjected to irritation and has ulcerated. The clinical features and treatment of the various forms of papilloma are considered with the individual tissues and organs.
#Adenoma.#--An adenoma is a tumour constructed on the type of, and growing in connection with, a secreting gland. In the substance of such glands as the mamma, parotid, thyreoid, and prostate, adenomas are met with as encapsulated tumours. When they originate from the glands of the skin or of a mucous membrane, they tend to project from the surface, and form pedunculated tumours or polypi.
Adenomas may be single or multiple, and they vary greatly in size. The tumour is seldom composed entirely of gland tissue; it usually contains a considerable proportion of fibrous tissue, and is then called a _fibro-adenoma_. When it contains myxomatous tissue it is called a _myxo-adenoma_, and when the gland s.p.a.ces of the tumour become distended with acc.u.mulated secretion, a _cystic adenoma_, the best examples of which are met with in the mamma and ovary. A characteristic feature of the cystic variety is the tendency the tumour tissue exhibits to project into the interior of the cysts, const.i.tuting what are known as _intracystic growths_. They are essentially innocent, but intracystic growths, especially in the mamma of women over fifty, should be regarded with suspicion and therefore should be removed on radical lines.
Transition forms between adenoma and carcinoma are also met with in the r.e.c.t.u.m and large intestine, and these should be treated on the same lines as cancer.
CARCINOMA OR CANCER
A cancer is a malignant tumour which originates in epithelium. The cancer cells are derived by proliferation from already existing epithelium, and they invade the sub-epithelial connective tissue in the form of simple or branching columns. These columns are enclosed in s.p.a.ces--termed alveoli--which are probably dilated lymph s.p.a.ces, and which communicate freely with the lymph vessels. The cells composing the columns and filling the alveoli vary with the character of the epithelium in which the cancer originates. The malignancy of cancer depends on the tendency which the epithelium has of invading the tissues in its neighbourhood, and on the capacity of the cells, when transported elsewhere by the lymph or blood-stream, of giving rise to secondary growths.
Cancer may arise on any surface covered by epithelium or in any of the secreting glands of the body, but it is much more common in some situations than in others. It is frequently met with, for example, in the skin, in the stomach and large intestine, in the breast, the uterus, and the external genitals; less frequently in the gall-bladder, larynx, thyreoid, prostate, and urinary bladder.
Tissues appear to be most liable to cancer when, having attained maturity, they enter upon the phase of decadence or involution, and this phase is reached by different tissues at different periods. It is not so much, therefore, the age of the person in whom it occurs, as the age of the tissue in which it arises, that determines the maximum incidence of cancer. Cancer of the stomach appears and attains a maximum frequency earlier than cancer of the skin; cancer of the uterus and mamma is more frequent towards the decline of reproductive activity than in the later years of life; rectal cancer is not infrequently met with during the second and third decades. There is evidence that the irritation caused by alcohol and tobacco plays a part in the causation of cancer, in the fact that a large proportion of those who become the subjects of cancer of the mouth are excessive drinkers and smokers.
A cancer may appear as a papillary growth on a mucous or a skin surface, as a nodule in the substance of an organ, or as a diffuse thickening of a tubular organ such as the stomach or intestine. The absence of definition in cancerous tumours explains the difficulty of completely removing them by surgical measures, and has led to the practice of complete extirpation of cancerous organs wherever this is possible. The boundaries of the affected organ, moreover, are frequently transgressed by the disease, and the epithelial infiltration implicates the surrounding parts. In cancer of the breast, for example, the disease often extends to the adjacent skin, fat, and muscle; in cancer of the lip or tongue, to the mandible; in cancer of the uterus or intestine, to the investing peritoneum.
In addition to its tendency to infiltrate adjacent tissues and organs, cancer is also liable to give rise to _secondary growths_. These are most often met with in the nearest lymph glands; those in the neck, for example, becoming infected from cancer of the lip, tongue, or throat; those in the axilla, from cancer of the breast; those along the curvatures of the stomach, from cancer of the pylorus; and those in the groin, from cancer of the external genitals. In lymph vessels the cancer cells may merely acc.u.mulate so as to fill the lumen and form indurated cords, or they may proliferate and give rise to secondary nodules along the course of the vessels. When the lymphatic network in the skin is diffusely infected, the appearance is either that of a mult.i.tude of secondary nodules or of a diffuse thickening, so that the skin comes to resemble coa.r.s.e leather. On the wall of the chest this condition is known as _cancer en cuira.s.se_. Although the cancer cells constantly attack the walls of the adjacent veins and spread into their interior at a comparatively early period, secondary growths due to dissemination by the blood-stream rarely show themselves clinically until late in the course of the disease. It is probable that many of the cancer cells which are carried away in the blood or lymph stream undergo necrosis and fail to give rise to secondary growths. Secondary growths present a faithful reproduction of the structure of the primary tumour. Apart from the lymph glands, the chief seats of secondary growths are the liver, lungs, serous membranes, and bone marrow.
It is generally believed that the secondary growths in cancer that develop at a distance from the primary tumour, those, for example, in the medullary ca.n.a.l of the femur or in the diploe of the skull occurring in advanced cases of cancer of the breast, are the result of dissemination of cancer cells by way of the blood-stream and are to be regarded as emboli. Sampson Handley disagrees with this view; he believes that the dissemination is accomplished in a more subtle way, namely, by the actual growth of cancer cells along the finer vessels of the lymph plexuses that ramify in the deep fascia, a method of spread which he calls _permeation_. It is maintained also that permeation occurs as readily against the lymph stream as with it. He compares the spread of cancer to that of an invisible annular ringworm. The growing edge extends in a wider and wider circle, within which a healing process may occur, so that the area of permeation is a ring, rather than a disc.
Healing occurs by a process of "peri-lymphatic fibrosis," but as the natural process of healing may fail at isolated points, nodules of cancer appear, which, although apparently separate from the primary growth, have developed in continuity with it, peri-lymphatic fibrosis having destroyed the cancer chain connecting the nodule with the primary growth. This centrifugal spread of cancer is clearly seen in the distribution of the subcutaneous secondary nodules so frequently met with in the late stages of mammary cancer. The area within which the secondary nodules occur is a circle of continually increasing diameter with the primary growth in the centre.
In the rare cases in which the skin of the greater part of the body is affected, the nodules rarely appear below the level of the deltoid or the middle third of the thigh, the patient dying before the spread can reach the distal portions of the limbs.
Handley argues against the embolic origin of the metastases in the bones because of the rarity of these in the bones of the distal parts of the limbs, because of the fact that secondary cancer of the femur nearly always commences in the upper third of the shaft, which harmonises with the intimate connection of the deep fascia with the periosteum over the great trochanter, thus favouring invasion of the bone marrow when permeation has spread thus far. He claims support for the permeation theory from the fact that the humerus is rarely involved below the insertion of the deltoid, and that spontaneous fracture of the femur is three times more common on the side on which the breast cancer is situated.
The tumour tissue may undergo necrosis, and when the overlying skin or mucous membrane gives way an ulcer is formed. The margins of a _cancerous ulcer_ (Fig. 57) are made up of tumour tissue which has not broken down. Usually they are irregular, nodularly thickened or indurated; sometimes they are raised and crater-like. The floor of the ulcer is smooth and glazed, or occupied by necrosed tissue, and the discharge is watery and blood-stained, and as a result of putrefactive changes may become offensive. Haemorrhage is rarely a prominent feature, but discharge of blood may const.i.tute a symptom of considerable diagnostic importance in cancer of internal organs such as the r.e.c.t.u.m, the bladder, or the uterus.
[Ill.u.s.tration: FIG. 57.--Carcinoma of Breast with Cancerous Ulcer.]
_The Contagiousness of Cancer._--A limited number of cases are on record in which a cancer appears to have been transferred by contact, as from the lower to the upper lip, from one labium majus to the other, from the tongue to the cheek, and from one vocal cord to the other; these being all examples of cancer involving surfaces which are constantly or frequently in contact. The transference of cancer from one human being to another, whether by accident, as in the case of a surgeon wounding his finger while operating for cancer, or by the deliberate introduction of a portion of cancerous tumour into the tissues, has never been known to occur. It is by no means infrequent, however, that when recurrence takes place after an operation for the removal of cancer, the recurrent nodules make their appearance in the main scar or in the scars of st.i.tches in its neighbourhood. In the lower animals the grafting of cancer only succeeds in animals of the same species; for example, a cancer taken from a mouse will not grow in the tissues of a rat, but only in a mouse of the same variety as that from which the graft was taken.
While cancer cannot be regarded as either contagious or infectious, it is important to bear in mind the possibility of infection of a wound with cancer when operating for the disease. A cancer should not be cut into unless this is essential for purposes of diagnosis, and the wound made for exploration should be tightly closed by st.i.tches before the curative operation is proceeded with; the instruments used for the exploration must not be used again until they have been boiled. The greatest care should be taken that a cancer which has softened or broken down is not opened into during the operation.
Investigations regarding the cause of cancer have been prosecuted with great energy during recent years, but as yet without positive result. It is recognised that there are a number of conditions which favour the development of cancer, such as prolonged irritation, and a considerable number of cases have been recorded in which cancer of the skin of the hands has followed prolonged and repeated exposure to the Rontgen rays.
_The Alleged Increase of Cancer._--Regarding the alleged increase of cancer, it may be pointed out that it is impossible to ascertain how much of the apparent increase is due to more accurate diagnosis and improved registration. It is probable also that some increase has taken place in consequence of the increased average duration of life; a larger proportion of persons now reach the age at which cancer is frequent.
_The prognosis_ largely depends on the variety of cancer and on its situation. Certain varieties--such as the atrophic cancer of the breast which occurs in old people, and some forms of cancer in the r.e.c.t.u.m--are so indolent in their progress that they can scarcely be said to shorten life; while others--such as the softer varieties of mammary cancer occurring in young women--are among the most malignant of tumours. The mode in which cancer causes death depends to a large extent upon its situation. In the gullet, for example, it usually causes death by starvation; in the larynx or thyreoid, by suffocation; in the intestine, by obstruction of the bowels; in the uterus, prostate, and bladder, by haemorrhage or by implication of the ureters and kidneys. Independently of their situation, however, cancers frequently cause death by giving rise to a progressive impairment of health known as the _cancerous cachexia_, a condition which is due to the continued absorption of poisonous products from the tumour. The patient loses appet.i.te, becomes emaciated, pale, and feverish, and gradually loses strength until he dies. In many cases, especially those in which ulceration has occurred, the addition of pyogenic infection may also be concerned in the failure of health.
_Treatment._--Removal by surgical means affords the best prospect of cure. If carcinomatous disease is to be rooted out, its mode of spread by means of the lymph vessels must be borne in mind, and as this occurs at an early stage, and is not evident on examination, a wide area must be included in the operation. The organ from which the original growth springs should, if practicable, be altogether removed, because its lymph vessels generally communicate freely with each other, and secondary deposits have probably already taken place in various parts of it. In addition, the nearest chain of lymph glands must also be removed, even though they may not be noticeably enlarged, and in some cases--in cancer of the breast, for example--the intervening lymph vessels should be removed at the same time.
The treatment of cancer by other than operative methods has received a great deal of attention within recent years, and many agents have been put to the test, _e.g._ colloidal suspensions of selenium, but without any positive results. Most benefit has resulted from the use of radium and of the X-rays, and one or other should be employed as a routine measure after every operation for cancer.
It has been demonstrated that cancer cells are more sensitive to radium and to the Rontgen rays than the normal cells of the body, and are more easily killed. The effect varies a good deal with the nature and seat of the tumour. In rodent cancers of the skin, for example, both radium and X-ray treatment are very successful, and are to be preferred to operation because they yield a better cosmetic result. While small epitheliomas of the skin may be cured by means of the rays, they are not so amenable as rodent cancers.
Cancers of mucous membranes are less amenable to ray treatment because they are less circ.u.mscribed and are difficult of access. In cancers under the skin, the Rontgen rays are less efficient; if radium is employed, the tube containing it should be inserted into the substance of the tumour after the method described in connection with sarcoma--and another tube should be placed on the overlying skin.
In the employment of X-rays and of radium in the treatment of cancer, experience is required, not only to obtain the maximum effect of the rays, but to avoid damage to the adjacent and overlying tissues.
Ray treatment is not to be looked upon as a rival but as a powerful supplement to the operative treatment of cancer.
VARIETIES OF CANCER
The varieties of cancer are distinguished according to the character and arrangement of the epithelial cells.
The _squamous epithelial cancer_ or _epithelioma_ originates from a surface covered by squamous epithelium, such as the skin, or the mucous membrane of the mouth, gullet, or larynx. The cancer cells retain the characters of squamous epithelium, and, being confined within the lymph s.p.a.ces of the sub-epithelial connective tissue, become compressed and undergo a h.o.r.n.y change. This results in the formation of concentrically laminated ma.s.ses known as cell nests.
The clinical features are those of a slowly growing indurated tumour, which nearly always ulcerates; there is a characteristic induration of the edges and floor of the ulcer, and its surface is often covered with warty or cauliflower-like outgrowths (Fig. 58). The infection of the lymph glands is early and constant, and const.i.tutes the most dangerous feature of the disease; the secondary growths in the glands exhibit the characteristic induration, and may themselves break down and lead to the formation of ulcers.
[Ill.u.s.tration: FIG. 58.--Epithelioma of Lip.]
Epithelioma frequently originates in long-standing ulcers or sinuses, and in scars, and probably results from the displacement and sequestration of epithelial cells during the process of cicatrisation.
The _columnar epithelial cancer_ or _columnar epithelioma_ originates in mucous membranes covered with columnar epithelium, and is chiefly met with in the stomach and intestine. As it resembles an adenoma in structure it is sometimes described as a _malignant adenoma_. Its malignancy is shown by the proliferating epithelium invading the other coats of the stomach or intestine, and by the development of secondary growths.
_Glandular carcinoma_ originates in organs such as the breast, and in the glands of mucous membranes and skin. The epithelial cells are not arranged on any definite plan, but are closely packed in irregularly shaped alveoli. If the alveoli are large and the intervening stroma is scanty and delicate, the tumour is soft and brain-like, and is described as a _medullary_ or _encephaloid cancer_. If the alveoli are small and the intervening stroma is abundant and composed of dense fibrous tissue, the tumour is hard, and is known as a _scirrhous cancer_--a form which is most frequently met with in the breast. If the cells undergo degeneration and absorption and the stroma contracts, the tumour becomes still harder, and tends to shrink and to draw in the surrounding parts, leading, in the breast, to retraction of the nipple and overlying skin, and in the stomach and colon to narrowing of the lumen. When the cells of the tumour undergo colloid degeneration, a _colloid cancer_ results; if the degeneration is complete, as may occur in the breast, the malignancy is thereby greatly diminished; if only partial, as is more common in rectal cancer, the malignancy is not appreciably affected.
Melanin pigment is formed in relation to the cells and stroma of certain epithelial tumours, giving rise to _melanotic cancer_, one of the most malignant of all new growths. Cyst-like s.p.a.ces may form in the tumour by the acc.u.mulation of the secretion of the epithelial cells, or as a result of their degeneration--_cystic carcinoma_. This is met with chiefly in the breast and ovary, and the tumour resembles the cystic adenoma, but it tends to infect its surroundings and gives rise to secondary growths.
_Rodent cancer_ originates in the glands of the skin, and presents a special tendency to break down and ulcerate on the surface (Figs. 102 and 103). It almost never infects the lymph glands.
DERMOIDS
A dermoid is a tumour containing skin or mucous membrane, occurring in a situation where these tissues are not met under normal conditions.
The _skin dermoid_, or _derma-cyst_ as it has been called by Askanazy, arises from a portion of epiblast, which has become sequestrated during the process of coalescence of two cutaneous surfaces in development.