means unusual. The statistics of operators vary a great deal. In 600 ovariotomies Schroeder found 50 papillomatous cysts-somewhat over 8 per cent. In the experience of the writer they have been very much more frequent than this.

The papillomatous cyst is the most dangerous cyst affecting the ovary. The danger lies in metastasis of the papillomatous growths to the general peritoneum. Metastasis occurs from the perforation of the cyst-wall and the escape into the peritoneum of the papillomatous

masses.

The tendency to rupture of the cyst-wall is one of the characteristics of this form of tumor. The wall becomes

FIG. 165.-Double papillomatous cyst of the ovary. The right cyst has ruptured and is turned inside out, showing a mass of papillomata. Papillomata have penetrated the wall of the left cyst. The peritoneum has been infected, and a papillomatous growth appears on the fundus uteri.

weakened by atrophy or fatty degeneration, or by direct pressure of the luxuriant papillary growths. These growths make their way to the outer surface of the cyst, and extend thence throughout the peritoneum; or, if rupture takes place, the cyst may become so inverted that the site of each ovary is occupied by a mass of papillomata; the formerly enclosing cyst has disappeared, and its remains can be discovered only by careful dissection (Fig. 165). Such a condition has undoubtedly often been mis

taken for primary papilloma of the ovary, the real origin in a papillomatous cyst not having been detected.

The secondary affection of the peritoneum is due not only to continuity of tissue, but to implantation and growth of portions of papillomata that have become broken off and carried to different parts of the peritoneal cavity. Such secondary growths may extend throughout the whole abdomen from the pelvis to the diaphragm, covering any of the viscera. They resemble in all respects the original papillomata found in the interior of the ovarian cyst. They sometimes form cauliflower-like masses as large as the fist, and may be palpated through the abdominal wall. They are very vascular, and bleed profusely on being handled. The smallest particles of papillomata are capable of infecting the peritoneum or other tissues in this way.

The escape of a small quantity of the cyst-fluid into the abdomen during the removal of the tumor may cause subsequent recurrence in the peritoneum. Secondary development of the growth in the abdominal cicatrix, or its appearance in the site of puncture after tapping, is due to the same cause.

Papillomata of the peritoneum are usually accompanied by ascites. This is a prominent symptom in those cases of papillomatous ovarian cyst in which secondary infection of the peritoneum has taken place. In rare cases ascites is present, though perforation of the cyst and involvement of the peritoneum cannot be detected.

Sometimes perforation of the cyst takes place into adjacent organs, especially if the growth be intra-ligamentous. In such cases the papillomatous masses may protrude into the bladder, the rectum, or the cavity of the

uterus.

CHAPTER XXX.

CYSTS OF THE PAROVARIUM.

THE parovarium consists of a series of fine tubules lying between the layers of the mesosalpinx. It may be seen in the fresh specimen by holding the mesosalpinx stretched between the eye and the light (Fig. 144).

The typical parovarium consists of three parts: a series of vertical tubules; a series of outer tubules free at one extremity; and a larger longitudinal tubule.

The vertical tubules range from five to twenty-four in number. They converge somewhat toward the ovary, where they end in blind extremities and become closely associated with the paroöphoron. At the other end they terminate in the larger longitudinal tubule.

The series of outer tubules are called Kobelt's tubes. They are free and closed at the distal extremity, while at the proximal extremity they join the longitudinal tubule. The larger longitudinal tubule is called the duct of Gärtner. It may sometimes be traced traversing the broad ligament to the uterus, and through the walls of this organ and of the vagina to its termination at the urethra. It corresponds to the vas deferens in the male. When persistent in the vaginal wall it may become the starting-point of a vaginal cyst.

The vertical tubes of the parovarium are from 0.3 to 0.5 millimeters in diameter. They are occasionally found lined with ciliated columnar epithelium. Usually they contain a granular detritus representing the remains of broken-down epithelium.

Cysts may arise from any of the parts of the parovarium.

Kobelt's tubes frequently become distended, and form

small pedunculated cysts about the size of a pea. They are of no clinical importance (Fig. 144). They are often observed in operations for ovarian disease, and are very often mistaken for the hydatid or the cyst of Morgagni which springs from the Fallopian tube, and which has already been described.

The difference between these two varieties of small

cysts may be determined by careful examination of the point of origin and by means of the microscope. Sutton states that the cyst of Morgagni has muscular walls and is lined by ciliated columnar epithelium. In the cyst of Kobelt's tubes the walls are fibrous and the lining is cubical epithelium.

Large cysts of the parovarium originate from the verti

cal or the longitudinal tubules, and usually remain sessile and develop between the layers of the mesosalpinx and the broad ligament. As the cyst grows and separates the layers of the mesosalpinx, it comes into close relationship with the Fallopian tube. This structure, being held by its uterine connection and the tubo-ovarian ligament, becomes stretched across the surface of the cyst and very much elongated. The elongation of the Fallopian tube is a very constant accompaniment of parovarian cysts. The tube may attain a length of 15 or 20 inches. The fimbria may also become much stretched and elongated by the traction of the growing cyst, and may attain a length of 4 inches.

The ovary is unaffected unless the cyst be of very large size, in which case the ovary may be stretched upon the surface of the cyst, so that its position becomes difficult to determine.

There are two varieties of parovarian cyst-the simple and the papillomatous.

The simple parovarian cyst has a very thin wall of uniform thickness. In small cysts, less than the size of a child's head, the wall may be transparent. It is of a light yellowish or greenish color, and the fine vessels ramifying upon the surface are plainly visible. As one would expect from the direction of growth, the outer covering of the cyst is peritoneum, which is not adherent and may be readily stripped off. The middle coat is composed of fibrous tissue containing unstriped muscle. The lining membrane is ciliated columnar epithelium, stratified epithelium, or simple fibrous tissue, according to the size of the cyst. The changes in the character of the epithelium are due to pressure. The cyst-contents are a clear, limpid, opalescent fluid of a specific gravity below 1010.

In the papillomatous parovarian cyst the interior is covered with warts or papillomatous growths resembling in every respect those that occur in the cyst of the paroöphoron, already described. The papillomatous parova