The primary alimentary canal was a continuous tube lined with a continuous layer of columnar epithelium. That portion connected with the yolk sac develops into the intestine, the balance into the central nervous canal. Portions of this canal are in postnatal life absolutely obsolete; others persist in a rudimentary condition. Dermoid cysts and dermoid tumors develop in connection with each of these. In some there is a large central cavity; others are almost absolutely solid. Thus we find dermoids in the coccygeal region, which have been variously regarded as sarcomas, adenomas, etc., which are really of origin as stated above and should be considered simply as dermoid tumors. Most of these project outwardly; some of them arise and develop within the pelvis. Dermoid cysts and tumors are also met with in connection with the rectum—sometimes between the rectum and the bladder, and between the rectum and the spine. Dermoid tumors are also found in connection with the pituitary body. These sometimes develop within the cranium, or, again, protrude perhaps into the orbit, perhaps into the pharynx.

Thyroid dermoids are tumors of great interest. They develop sometimes about the craniopharyngeal canal, which may be detected as a small canal in the macerated sphenoid bone of a fetus, and which before birth is filled with fibrous tissue. It connects with a recess in the middle line and at the base of the skull, presenting in the pharynx, which is often referred to as the bursa pharyngea. It is around this recess that the lymphoid tissue known as the “pharyngeal tonsil” develops. It may be thus expected that the roof of the pharynx should be the occasional site of dermoids. It is from the pharynx or the floor of the mouth that in vertebrates the thyroid body arises. In higher forms it becomes dissociated from the pharynx and shifts its position. The thyroid body is developed around the thyroid duct, which first appears as the thyrohyoid duct, which later becomes divided, that portion in relation with the tongue becoming the thyrolingual duct, the remaining portion persisting as the thyroid duct. These are present about once in every ten subjects, according to Sutton, the canal when persistent being lined with epithelium. When the extremities of these ducts become occluded retention cysts may form. In the same way dermoids of the tongue are formed, similar to those occurring on the scalp. These are frequently mistaken for sebaceous cysts. They may be unilateral, central, or even bilateral. The lingual duct is also of interest, because it would appear that certain cases of epithelioma of the tongue arise along this duct, and perforating malignant ulcer of the tongue is thus produced. Dermoid tumors of the lingual or thyroid ducts resemble in structure the thyroid body. The thyroid duct may also be detected in many adults running from the isthmus of the thyroid body to the posterior aspect of the hyoid bone, and surrounded by muscle tissue. Sometimes the space usually occupied by this duct is represented by a series of detached bodies known as accessory thyroids. These are not infrequently the seat of cysts, sometimes of considerable size. (The accessory thyroids often enlarge when the main thyroid has been extirpated for disease.) Thus cysts in close relation to the hyoid bone are common. Some of them grow slowly, while others grow rapidly and contain much fluid. Many of them are unilateral, and are often mistaken for enlargements of one lobe of the thyroid. Cysts growing from accessory thyroids are often filled with papillomatous masses, and are occasionally the seat of malignant degeneration.

In the omphalomesenteric duct or its remains, especially in relation with the umbilicus, we often meet with small cysts or tumors in infants and young children. When the duct is persistent it presents normal intestinal structure, and, like the appendix, possesses much adenoid or lymphoid tissue.

Another and very important form of tubulodermoids develops in connection with the branchial clefts of the neck. Congenital fistulas of the neck have been long known, but only comparatively recently understood. Of the branchial clefts it is well known that the first alone should persist, as the Eustachian tube. Occasionally, however, they fail to become obliterated, and then we have congenital tumors or cysts, which may, perhaps, not develop to appreciable size until somewhat late in life; or there may be fistulous passages opening either into the pharynx or externally, forming canals varying in length from half an inch to two inches, secreting a little fluid because lined with epithelium. When these become inflamed an abscess results. When they open externally the opening is often marked by a little tag of skin containing a fragment of yellow cartilage. These are often referred to as cervical auricles. They open along the line of the sternomastoid muscle. The internal openings of these fistulas frequently form diverticula from the pharynx or esophagus. Thus it will be seen that dermoid cysts about the neck are principally relics of openings or ducts, which are normal in embryonic life, but which should have been obliterated at or long before birth. Congenital fistulas, however, may be met with in the middle line of the neck, which are not to be confounded with branchial fistulas, but rather with the ducts previously described.

3. Ovarian Dermoids and Teratomas.

—These may be unilocular or multilocular cysts, usually the latter. They are lined with epithelium, and contain mostly mucoid fluid, the inner coat being practically identical with mucous membrane. Occasionally, however, the skin is furnished with hair, sebaceous glands, teeth, and even nipples. The multilocular cysts are practically an aggregation of those just described. They are surrounded by dense capsules, often attain great dimensions, and are made up of primary cysts resembling large cavities in a honeycomb-like mass, which itself is occupied by secondary cysts, and belong rather to the class of mucous retention cysts, these being occupied by still smaller ones, which are histologically indistinguishable from distended ovarian follicles. In these large tumors we find in some cases hair, in others teeth, and in others sebaceous glands, etc., the dermoid constituents being scattered throughout. As Wilms has shown, in almost every tumor of this character a projection may be found whose summit is covered with epiblastic elements, which when cut in serial transverse sections will show in its deeper portion other epithelial collections representing a feeble attempt to develop a nervous system, or lung tissue, while mesoblastic elements, like connective tissue, cartilage, and bone, appear scattered throughout, as though a very crude effort had been made to reproduce an atypical embryo.

3. Teratomas.

So far the endeavor has been to limit the term dermoid to tumors which are essentially of epiblastic formation, their location being explained on the inclusion theory of Cohnheim. There is also a still more complicated type of tumor, composed of tissues of both epiblastic and mesoblastic origin, perhaps even hypoblastic. Their consideration belongs to that department of pathology known as teratology, which is supposed to deal especially with monsters. Strictly speaking a teratoma refers to an irregular tumor or mass containing tissues and fragments of viscera of a suppressed fetus which is attached to an otherwise normal individual. Nevertheless the term is often applied to growths which are the result of luxuriant mesoblastic development in which neither form nor member of a suppressed fetus is present.

The presence of supernumerary members is largely connected with what is called dichotomy, alluding thereby to cleavage either at the anterior or posterior end of the developing embryo. When the whole embryonic axis divides twins may be produced, but should cleavage be partial we may have a monster with two heads if it be anterior, or one with three or more limbs if it be posterior. Children born with these deformities are usually called monsters, and the study of such cases belongs entirely to teratology. But in certain tumors small portions of a suppressed fetus may develop, as, for instance, from the posterior portion of the sacrum, or within the abdomen or thorax, or upon the neck or face, which on dissection may contain a few vertebrae or processes resembling fingers associated perhaps with a structure resembling intestine or liver. This should be called a teratoma. Such tumors possess for the pathologist the greatest value. In surgery, however, they are rare, and there are scarcely two cases alike. The question of operation will often arise, as it does with supernumerary limbs, and each case should be studied upon its own merits. Sometimes they are amenable to extirpation.

Embryonal Adenosarcoma.

—Embryonal adenosarcoma is a term given to certain teratomatous tumors peculiar to renal and adrenal structure, which present peculiar characteristics in the mixture of elements which enter into their composition. At various times these tumors have been called adenoma, sarcoma, rhabdomyoma, congenital cystic kidney, etc. They have been also likened to the thyroid. They comprise a group of neoplasms, always congenital in origin, which usually appear early in life, but occasionally occur in advanced adult life. One of the most marked specimens of this kind the writer removed from a man over fifty years of age. Most of the specimens, however, described in literature pertain to the young. On minute examination they often present a strange, mixed picture of voluntary muscle elements intermingled with epithelium arranged to imitate acinous glands, with cystic dilatations of the true kidney tissue. They often attain enormous size, and undergo such proliferation of mesoblastic elements as to resemble sarcoma. Their occurrence is to be explained only on the principles of Cohnheim’s hypothesis. When the original Wolffian body is being differentiated from the elements about it a confusion of the same with the excretory tubular beginnings, which are to empty into the Wolffian duct, occurs. Thus we have the commencement of a mixed mass which presents itself as a more or less rapidly growing tumor, in which even cartilage or other mesoblastic structures may be met with. It is scarcely possible that any two specimens should yield exactly the same microscopic picture, much depending on whether one element or the other prevail. In a few of them there may occur also a mixture of adrenal elements. Sometimes the renal structure itself is more or less distinct, and rides, as it were, upon the surface of the tumor; at other times it is entirely mixed up with it. While the condition is usually limited to one side it may be a double affection, so that the second kidney becomes useless and the patient succumbs. The only treatment is extirpation.

Teratomatous tumors are sometimes found hanging in the pharynx, attached by a small pedicle, where they may be confounded with dermoids unless carefully examined after removal. Many instances of this type of tumor are found in animals. Here no false sentiment will prevent complete examination and preservation of the specimen. They are also encountered in the sacral and coccygeal regions.

4. Tumors of Connective-tissue Type.

Lipoma.

—Lipomas, or tumors composed of fat, are the most common of the neoplasms. Their normal type is the ordinary adipose tissue of the body, and may be divided into the encapsulated and the diffuse, the former of which are surrounded by fibrous tissue. The diffuse lipomas are those which have no capsule, and where the pathological collection of fat merges into that normally present—in other words, they are not circumscribed.

Subcutaneous Lipomas.

—Subcutaneous lipomas are perhaps the most common of all, and are usually irregularly lobulated and encapsulated, adherent rather to the skin than to the deeper tissues. Usually but one is found in an individual, though instances of multiple lipomas are not rare. They develop sometimes to enormous size, cases being on record where the tumor has even weighed one hundred pounds. They may be met with at any point on the surface of the body. The lobules often burrow between the muscles, and those found in the palm of the hand penetrate even beneath the palmar fasciæ. They are sometimes markedly pedunculated, and often hang by a small stem. The diffuse subcutaneous lipoma is most common about the neck, in the groin, and in the axilla.

Subserous Lipomas.

—Subserous lipomas are mostly retroperitoneal, and large tumors of this character, mistaken for ovarian, have been successfully removed by operation. They also occur in the hernial canals and spaces. They develop beneath the peritoneum covering the intestines, and in this location give rise occasionally to intussusception. Here in their pathological development they have the general form and significance of appendices epiploicæ.

Subsynovial Lipomas.

—Subsynovial lipomas occur about various joints and tendon sheaths; within the knee they assume a distinctive type which has been called lipoma arborescens, where they take on a dendritic appearance and arrangement. Submucous lipomas are rare. Intermuscular fatty tumors are occasionally met with, an interesting variety being that which develops between the masseter and buccinator muscles. Intramuscular forms rarely occur, as well as a variety known as parosteal, which arises in connection with the periosteum. Fatty tumors also occur within the spinal dura, as well as outside of it within the spinal canal, and more or less lipomatous alterations are common in connection with spina bifida.

Lipomas are ordinarily easy of recognition, save when deeply located. The subcutaneous forms are intimately related with the overlying skin, and have a dough-like consistence which is usually pathognomonic. Tumors, suspected to be fatty, in the middle line of the back or cranium are always to be viewed with suspicion, as they are often connected with congenital meningeal protrusions.

An encapsulated lipoma when thoroughly removed will not return.

Mixed forms of fibrous and fatty neoplasm are occasionally seen, and are referred to as lipoma fibromatosum or fibroma lipomatosum, according as one or the other tissue predominates. These growths are innocent in their character, but call for thorough extirpation. They frequently give rise to considerable discomfort or pain, and are called lipoma dolorosa.

Fibroma.

—Fibromas are tumors composed of fibrous tissue, which, when of pure type, are found to be not so common as was formerly supposed, the majority of tumors hitherto roughly grouped as fibromas containing either muscle tissue or sarcomatous elements, which takes them out of the category of pure fibroma. A typical fibroma is ordinarily dense, and is composed of wavy bundles of fibrous tissue whose cells are long and slender and closely packed together, the mass being permeated by distinct bloodvessels.

Fibroma occurs most commonly in the ovary, the uterus, the intestine, the gum (epulis), in nerve sheaths, and in the skin in the form of so-called painful subcutaneous tubercles and molluscum fibrosum. There is also a fibrous tumor of the skin, known as keloid, sustaining to fibroma the same relation that exists between exostosis and osteoma.

Painful subcutaneous tubercle is a sample of pure fibroma in the shape of a small, flattened, pea-like tumor which never attains great size. It is situated loosely in the subcutaneous structure and may form a visible prominence. Insignificant as it would thus appear, it becomes the seat of exasperating pain, particularly when touched or handled, which may radiate to considerable distances. The etiology of these growths is unknown.

In the ovary, the uterus, the intestine, and the larynx true fibrous tumors are pathological curiosities rather than common lesions.

Epulis.

—Epulis means any tumor growing upon the gum. The term was formerly applied in an indistinct and too comprehensive way, although it is still retained in literature. But pure fibromas do spring from the fibroösseous structure of the gum and alveolar process. They are covered with the gingival mucous membrane and seem to spring from the periodontal membrane. They seldom attain large size, and then only by neglect. By the pressure of such tumors teeth may be separated and distortion of the mouth produced. They should be promptly extirpated.

Keloid.

—Keloid is a fibrous neoplasm arising mainly in cicatricial tissue, which is essentially fibroid in structure. It is a neoplasm which often follows the general outline of the scar in which it grows, consists in elevation of the surface, ordinarily quite smooth, sometimes of a delicate pink from the dilated vessels which it contains. Keloid is the bête noir of surgeons, as it frequently complicates and disfigures scars which have at first been satisfactory, and since it indicates a condition which it is discouraging to deal with, because when it is removed there is usually recurrence of growth within a few months after cicatrization. It often occurs in stitch-hole scars and upon the site of extensive burns, and may be observed after puncture of the ears for ear-rings, and has also been observed in scars left by smallpox, acne, etc. It is more prevalent in the colored race than in the white. In negroes multiple keloid tumors are often seen, occasionally in large numbers. Their explanation is unknown, and it may be that some trifling injury has preceded each individual tumor (Fig. 74).

The treatment of keloid will be considered in the chapter on the Surgical Diseases of the Skin.

Desmoids.

—This term has been applied to tumors of a certain clinical type which arise from the fibrous structures, usually of the abdominal wall, and produce neoplasms like the fibromas of other parts of the body. The use of the term should be restricted to those tumors which proceed primarily only from muscles, tendons, and aponeuroses, or perhaps from ligamentous and periosteal tissues. These tumors are usually single, attain sometimes considerable size, grow slowly, rarely involve other structures, and not infrequently develop to such an extent as to encroach upon either pelvis or the abdomen, or both. They have been known to attain to the weight even of ten pounds or more. They are usually more or less encapsulated, and are firm and dense in structure. Under the microscope they have the general appearance of cellular fibroma. Sarcomatous elements may be met, while they occasionally undergo cystic degeneration. Their occurrence may be explained, at least in some instances, on the embryological theory of Cohnheim.

The treatment of desmoids consists in their complete extirpation. They should not be allowed to attain large size because their removal may entail a serious weakening of the abdominal wall. There should be such plastic rearrangement of abdominal protecting membranes as to reduce the resulting weakening to a minimum.

Psammoma.

—Psammoma is a term applied to a form of hard fibroma met with in the dura mater, in which there has occurred a petrefaction of some of the cells—i. e., a deposition of calcareous salts, which gives it a gritty or sandy appearance.

Chondroma.

—The true chondroma is a tumor composed of hyaline cartilage. It occurs in the long bones, usually in relation with epiphyseal cartilages, and is often noted during the earlier years of life. While it is usually a solitary tumor, multiple chondromas are often seen, especially upon the hands. These tumors are often encapsulated and form deep hollows, in which they rest. Unless pressing upon nerve trunks they are painless and slow of growth. They are exceedingly dense and hard, and ordinarily immovable. Mucoid softening (i. e., cystic degeneration) is common, and the softened areas may give rise to fluctuation. There may be coincident calcification or ossification in any of these growths. It is noted as a curious circumstance by Sutton that their tissue resembles histologically the bluish, translucent, epiphyseal cartilage seen in progressive rickets.

To the small local hypertrophies of cartilage which are seen especially about joints, about the laryngeal cartilages, and the triangular cartilage of the nose, are given the term ecchondroses. They are most common in the knee in connection with rheumatoid arthritis, and occur as prominences along the margins of the joint cartilage. They may project to such an extent as to be detached by accident, after which they become movable and floating bodies in the joints. Many of the floating cartilages or bodies found in joints are detached ecchondroses, which may be smoothed off by attrition, and may be found singly or multiple, even several hundred existing in one joint.

Chondromatous changes as occurring in sarcomatous tumors have been alluded to. It seems to be easy for connective tissue to form hyaline cartilage, and mixed tumors may thus be seen in connection either with sarcoma, fibroma, or other forms.

Treatment.

—The treatment of chondroma is solely operative. Unless the integrity of a member or a limb be compromised, such a tumor can usually be shelled out from its location, but requires that the matrix be completely extirpated; all of which may call for the use of powerful bone instruments. At other times amputation is the only measure which may relieve from deformity, pain, and disability. The ecchondroses occurring within joints necessitate incision and evacuation, with the most rigid aseptic precautions, with or without drainage. When practised according to modern technique this is almost invariably successful. In former times many lives were lost because of septic infection.

Osteoma.

—Under the head of nomenclature I have already endeavored to distinguish as between exostosis, or irregular bone outgrowth, and osteoma, as a distinct tumor which is composed of bone tissue, with the subvariety odontoma, or tumors of dental origin and structure. Osteoma is regarded by some as ossifying chondroma, for it is nearly always found near epiphyseal lines, and is always covered by hyaline cartilage when thus found. Nevertheless it is not invariably such. We speak of compact or ivory osteoma and of a cancellous form. The former is identical with the compact tissue of the shafts of long bones, and may occur anywhere, but is most common about the cranium, at the frontal sinus, the external meatus, and the mastoid process. Osteomas growing into the frontal sinus of oxen form large, lobulated, bony masses, sometimes weighing several pounds, and as dense as ivory. Some of these tumors growing into the cranial cavity have been regarded as ossified brains. Osteomas in connection with the external auditory meatus may partially obscure this channel and cause deafness. They constitute ivory-like growths, which sometimes defy the finest steel instruments with which the surgeon can supply himself.

Cancellous osteomas grow in the cranium as well as in the long bones, and, like the compact forms, only occasion pain by pressure upon nerve trunks.

Exostoses.

—Exostoses are classed by Sutton as—

1. Those formed by ossification of tendons and their attachments. There should be excluded from this group such natural or evolutionary processes as the supracondyloid process, the third trochanter of the femur, etc. Over or around such exostoses bursæ will form to mitigate as much as possible the effect of friction. Such an outgrowth is known as an exostosis bursa; it is most frequently seen on the inside of the femur immediately above the knee.

2. Subungual exostoses, occurring usually beneath the nail of the big toe.

3. Exostoses due to calcification of inflammatory exudations, including the rare condition known as myositis ossificans.

When a true osteoma is once thoroughly removed there is no tendency to recurrence. Thorough removal, however, calls sometimes for serious and often mutilating operations, which may become dangerous when the growth involves the curve of a rib or a large portion of the skull. At other times amputation is rendered necessary. Special forms require special treatment.

Sarcoma.

—Formerly this name implied a fleshy tumor, and was made to cover many different conditions. Now sarcoma means a tumor composed of immature mesoblastic or embryonic tissue in which cells predominate over intercellular material. Sarcomas are sometimes encapsulated; they merge into and infiltrate the surrounding tissue and disseminate widely, and have usually these propensities and characteristics to such a degree as to constitute malignancy. For the laity sarcomas and carcinomas are together included in the comprehensive term of cancer; for the surgeon they constitute but one form of cancer. Sarcomas are classified, according to the shape of their cells and their disposition, into—

• A. Round-cell;
• B. Spindle-cell;
• C. Myeloid.

To these are added other varieties mentioned below.

A. Round-cell Sarcoma.

—This is simple in construction, and consists of round cells containing very little intercellular substance. The nuclei of the tumor cells stain easily, the cells themselves varying in size in different cases. Bloodvessels lead up to the tumor, but in the interior appear rather as channels. These tumors have no lymphatics: they grow rapidly, infiltrate easily, recur quickly, and give rise to numerous metastatic or secondary deposits. They may affect any part of the human body. The size of the cells is supposed to be in some measure an index of their malignancy—the smaller the cell the more malignant the tumor. They appear at all periods of life. They are perhaps the most commonly seen of malignant tumors in animals. (See Plate XVII.)

Lymphosarcoma.

—This tumor is composed of cells similar to the previous form, but enclosed in a delicate meshwork resembling that of lymph nodes, hence the term lymphosarcoma. Lymphosarcomas are not to be confounded with enlargements nor with the specific granulomas involving these lymphatic structures.

B. Spindle-cell Sarcoma.

—In this form the cells have a spindle shape and run in all directions, so that sections will show them in various shapes and sizes. In some cases the cells are small and slender, in others large. The size of the cell is a measure of the malignancy of the tumor. (See Plate XVII.)

The largest of these spindle cells are frequently striated transversely like voluntary muscle fiber, and tumors composed of this form have been considered as tumors of striped muscle tissue, and are generally called rhabdomyoma. There is no tumor of striped muscle fiber, and the rhabdomyomas of writers generally should be considered as spindle-cell sarcoma, or may be dignified by the name myosarcoma. (See Rhabdomyoma, under Myoma.)

Alveolar Sarcoma.

—This is a rare form, in which the cells, contrary to the general rule of sarcomas, assume an alveolar arrangement strongly imitating that of epithelial cells in carcinoma. Almost invariably, however, on close examination it will be possible to distinguish a delicate reticulum between individual cells, which is never met with in cancer.

C. Myeloid, or Giant-cell Sarcoma.

—In this form the tissue resembles histologically the red marrow of young and growing bone, containing large numbers of multinuclear cells embedded in a matrix of spindle or round cells. These tumors usually occur in the long bones, and when freshly cut look like a piece of liver. They constitute most of the epulides or cases of epulis—i. e., spongy tumors springing from the gums. (See Plate XVIII., Fig. 2.)

Giant or multinuclear cells should be present in considerable numbers to entitle a tumor to classification in this group. When round cells, spindle cells, or giant cells mingle in nearly equal proportion the tumor should be called a mixed-cell sarcoma.

D. Osteosarcoma.

—Osteosarcoma is something more than sarcoma of bone, which latter may spring from the fibrous or medullary elements. It is sarcoma of the specific bone-forming connective tissue, including the osteoblasts and osteoclasts; in other words, of the stroma of the bone. Under these circumstances real bone develops throughout the tumor, and it is essentially a bony neoplasm. In like manner there may be true osteofibroma. These tumors are to be distinguished, even clinically, from the medullary sarcomas, which develop within the bone and expand it, even to enormous proportions, the bony covering then being a mere shell.

E. Chondrosarcoma.

—Chondrosarcoma resembles osteosarcoma in that it is sarcoma of the stroma of cartilage, or of the specific tissue which produces cartilage. In it true cartilage (white fibrous) also is found throughout the tumor. Chondrofibroma is also possible. (See Plate XIX.)

F. Endothelioma.

—Endothelioma has been called various names, and its true character has been only lately determined. It is composed particularly of the endothelial cells which line the lymph spaces, and which have no peculiar secretion. It is met with most often in the skin (especially of the face), in the parotid region, in the genital glands, the bones, the lymph nodes, and dura.

The microscopic picture of these tumors varies greatly, the endothelial cells often shaping and grouping themselves so as to imitate epithelioma. In doubtful cases the primary location or origin of the growth should be ascertained.

Endotheliomas are mainly of rapid growth, and often show a high degree of malignancy. If thoroughly extirpated before metastasis has occurred, prognosis is fair; but metastases happen early because of the direct connection of the tumor with the lymph current.

G. Angiosarcoma.

—Angiosarcoma is a sarcoma arising from the adventitia of the bloodvessels. It is characterized by its extraordinary vascularity, the ease with which hemorrhages into the structure of the tumor take place, and the frequency of pigmentation. Peritheliomas constitute a subvariety, met with especially in the kidneys, the bones, and the skin, and originate in the perithelial cells between the capillaries and the perivascular lymph spaces. They are more vascular than the angiosarcomas. The latter are common in the liver. In many cases the cells of these tumors simulate the columnar epithelium of adenocarcinoma. (See Plate XVIII, Fig. 1.)

H. Cylindroma.

—This is a term applied to tumors of the angiosarcomatous type in which hyaline changes have occurred, so that along the vessels appear cylindrical masses of altered cells. Similar appearances are noted in certain endotheliomas and are due to the same hyaline degeneration.

I. Melanosarcoma (better known as Melanoma).

—This refers to the deposition of pigment, rather than to type or shape of cell, the distinguishing feature of these growths being the presence both in the cells and in the intercellular substance of a variable quantity of blackish pigment. Of all the forms the melanotic growths are considered the most malignant. They invariably recur after removal, lead to secondary deposits at long distances, and present the most intractable and incurable forms of cancer. Deposition of pigment in carcinomas is most rare, if ever met with, and the growths of melanotic type should be relegated entirely to the class under consideration. The tumors most often develop from pigmented nevi of the skin, though primary melanoma of the deeper parts of the body is known. These will be treated more fully in the chapter on the Skin. (See Plate XX.)

This name has been variously applied by different writers to different growths. In order to avoid confusion it would be well, in using it, to be definite.

General Characteristics of Sarcomas and Endotheliomas.

—The vascular supply of sarcomas varies within wide limits. In nearly all instances it is of capillary character, the blood circulating rather through vessels without well-marked walls. While large vessels may be found about and in the periphery of these tumors, distinct vascular structure is usually absent from the more internal portions, which will explain the frequency of hemorrhage, its persistency after operation, and the ease with which large extravasations occur. True hematocele may thus take place within sarcomatous tumors, with the usual later cystic alterations, and thus in one way we have the condition known as cystosarcoma.

In attacking these growths the vascular and bloody area may be met just about their margins, the bloodvessels expanding as they arrive at the tumor, and sometimes bleeding extensively. Under most circumstances, however, this hemorrhage can be controlled by packing or by operating at a greater distance from the circumference of the growth.

Metastasis in sarcoma is common, dissemination occurring mainly along the veins, as these growths connect with the venous channels and permit of easy detachment of fragments, which are then carried along as emboli. These emboli pass naturally to the right side of the heart, and thence to the lungs, where it is most common to find secondary growths, except in areas emptying into the portal veins, in which case the liver will be the most common site. Sarcomas are destitute of lymphatics, and dissemination does not occur through these channels.

Infiltration is also a common phenomenon with these growths. This is generally seen in muscular tissue, particularly with growths proceeding from the periosteum and projecting into it.

Sarcomas, like other tumors, tend to grow along the lines of least resistance. Hence processes of these tumors will insinuate themselves into fissures and interspaces, and penetrate perhaps even into the cavities, from which it is hazardous or impossible to remove them. Thus, sarcomas springing from the head of a rib have been known to extend through an intervertebral foramen and give rise to an intraspinal tumor, causing fatal pressure.

Secondary changes are usually seen in sarcomas, the most frequent being hemorrhage. Myxomatous degeneration is also frequent, and gives rise to cystic conditions. Calcification is common, particularly in the slowly growing tumors which arise from bone. Upon the other hand, necrosis (i. e., ulceration) is common in growths which project upon the surface or into any of the open cavities of the body. Ulceration here is growth at a rate faster than nutrition will justify, and gangrene is to be regarded as a failure to supply sufficient blood. It may also mean infection, of which it is a usual expression.

Tumors of this character, which luxuriate upon reaching the surface, and bleed easily upon the slightest touch, were formerly known as fungus hematodes. The name may be preserved for the sake of convenience, but should be held to mean, in almost every instance, a rapidly growing round-cell sarcoma.

Sarcoma is common in the lower animals, particularly so in horses—most common in those of gray color. It is met with also in cows and various other domestic and undomesticated animals.

Myxoma.

—The myxomas are composed of mucous tissue, whose best-known normal representative is the Whartonian jelly of the umbilical cord. True myxoma should be distinguished from myxomatous degeneration, which occurs frequently in cartilage, fibrous tissue, and sarcoma, and which brings about a similar condition of affairs, though of essentially different origin. Myxomas appear under the following forms:

1. Polypi.

—These include many of those which grow in the nose. The pure form of nasal myoma proceeds from the mucous membrane of the nasal passages or sometimes from the accessory sinuses. But most of the so-called nasal polypi are due to edematous hypertrophies of the submucosa. The polypi usually hang as gelatinous tumors of grayish-yellow tint, being present sometimes singly, sometimes in clusters or in large numbers. Their principal effect is to produce nasal obstruction, with, perhaps, subsequent serious disorder, due to decomposition or to extension into the pharynx or other cavities. Similar growths also occur from the mucous membrane of the tympanum, and constitute the common variety of aural polypi.

2. Cutaneous Myxoma.

—Cutaneous myoma is not common. It presents usually as a sessile tumor, although about the perineum and labia the tumors may become pedunculated. It is often difficult to distinguish between a myoma of the skin and a sarcoma of the same which has undergone myxomatous degeneration, and which then should be called sarcoma myxomatodes. The latter tend to recur after removal; hence the importance of exact diagnosis.

3. Neuromyxoma.

Neuromyxoma is a similar condition involving the nerve trunks, and is dealt with under Neuroma.

Myxomas require complete removal, and, in the nose especially, cauterization or destruction of the surface from which they spring. When this is thoroughly done they do not recur; otherwise, they are likely to require subsequent operation.

Myoma.

—The true myoma is a tumor composed of unstriped or involuntary muscle fiber. Until recently it has been customary to divide the myomas into the leiomyomas in contradistinction to the rhabdomyomas, the latter being supposed to be tumors of voluntary muscle fiber. Myomas are met with only where involuntary muscle fiber is found—namely, in the uterus and adnexa, the vagina, the esophagus, alimentary canal, the prostate, the bladder, and the skin. They form encapsulated tumors composed of fusiform muscle cells with a rod-like nucleus, the size of the cells varying greatly in different specimens. The bundles of muscle fibers are much contorted, and it is often difficult in a single section to decide to just what class of cells they belong.

These tumors are most common in and about the uterus, and are referred to as intramural when developing in the true uterine tissue, and submucous and subserous when situated just beneath one or the other of the adjoining membranes. They differ in their rate of growth, are firm in composition, and are moderately vascular, sometimes containing areas of softening and becoming even cystic. In rare instances they become enormously vascular, and are then known as cavernous myomas. Aside from mucoid or colloid changes they occasionally undergo fatty metamorphosis or calcareous infiltration. The latter is possible to such an extent as to lead to a condition of uterine calculi.

Uterine myoma is liable to septic infection, which frequently follows exploration of the uterus or the changes incident to pregnancy or parturition. It then becomes a case for immediate operation. Uterine myomas do not occur before puberty, rarely before the age of thirty-five, and are most common between the thirty-fifth and forty-fifth years of life. They produce disaster not alone by their size, but by hemorrhage, by pressure on adjoining viscera (rectum, kidneys, etc.), and occasionally by torsion of a long pedicle.

Myomas are found in the esophagus, in the walls of the stomach, where they are frequently confounded with malignant tumors, in the prostate and wall of the bladder, and in connection with the skin. As soon as they give rise to inconvenience or to dangerous symptoms they are to be dealt with surgically, as no other treatment has proved of lasting benefit.

The rhabdomyomas deserve but brief description. The striated muscle fibers of which these tumors are composed have been often confused with spindle-shaped sarcoma cells. They are met with almost exclusively in the mixed tumors of the kidney under Teratomas.

Myoma or myofibroma is exceedingly likely to undergo sudden conversion into a form of growth entitling it to be called malignant myoma.

Angioma.

—Angiomas are tumors composed of bloodvessels, and group themselves under three headings, in accordance with the structure of the vascular system:

1. Capillary Angioma, or Nevus.

—Capillary angioma, or nevus, is the most common form of all, and is frequently seen in the skin and subcutaneous tissue. When the condition is spread over a relatively large area it gives rise to a discoloration known as port-wine mark, and called telangiectasis by the pathologists. The condition is often congenital or begins soon after birth. The color of the affected area determines whether the vessels belong to the venous or to the arterial system. These tumors may be found in all parts of the body, on the surface, on the submucous surfaces of the tongue, the inside of the mouth, the conjunctiva, and the vulva. The tendency is toward gradual increase in size; rarely, spontaneous contraction and obliteration occur.

2. Cavernous Tumors.

—These are similar in structure to the corpus cavernosum, and are called erectile tumors. They are common in connection with the skin, and are exaggerated forms of the variety first described, the vessels becoming not merely dilated but cavernous in arrangement. They occur occasionally in the tongue, in the voluntary muscles, and in the liver, and are noted very rarely in the mammæ, in the larynx, and subperitoneally.

A similar condition is met with in the so-called cavernous tumors which involve various organs, especially the thyroid and the liver. In these instances a part or the whole of the organ may be involved, and presents great increase in size and evidences of vascularity.

In cavernous growths of the thyroid are vessels, veins especially, the size of the thumb, while with the ear not touching the body of the patient a distinct venous murmur may be heard.

3. Arterial or Plexiform Angiomas.

—Arterial or plexiform angiomas, when of any particular size, are called cirsoid aneurysm or aneurysm by anastomosis. This form consists of arteries abnormal both in number, length, and diameter, tortuous in arrangement, occurring often in the scalp, but rarely in the perineum or genitalia, and seldom in other parts of the body. (See Aneurysm, Chapter XXIX.) These tumors are liable to rupture from external injury, and necessitate ligation of the main arterial trunks, with perhaps extirpation of the tumor mass.

Recognition of angiomas is not difficult unless they are deeply concealed. The effect of intermitting pressure, the emptying and refilling, and the distinction between arterial and venous growths by the result of alternating pressure and relaxation, either above or below the growth, with discoloration of the skin, and, in the larger growths, audible murmur, leave little doubt of the character of the growth.

When such growths are small they may be dealt with by electrolysis, the needles from both poles being introduced, or that from the negative, the positive being applied upon some neighboring portion of the body. The effect of the electric current is to determine coagulation of the blood in the tissues acted upon, and this is followed by organization of thrombus, conversion of vascular into cicatricial tissue, shrinkage, and possible eventual disappearance of the mass. Radical excision under an anesthetic should be made, dissecting out the mass, securing bleeding vessels, and reuniting the parts by sutures, with the expectation of securing primary union. This is the quickest and in many cases the least disfiguring method. Old methods of ligation of surrounding vessels or the subcutaneous ligature are now practically discarded. The injection methods as formerly practised, especially the use of iron salts in solution, are severely condemned, as death is liable to occur. With electrolysis and excision the surgeon has nearly all the measures which he will need to practise for the medical treatment of angiomas.