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.