rian cyst exhibits the same clinical features, and is liable to the same accidents, as the paroöphoritic cyst. It may become perforated and infect the general peritoneum.

The walls of the papillomatous parovarian cyst are somewhat thicker than those of the simple parovarian cyst; the fluid contents are not so clear and limpid, and may contain altered blood that has escaped from the papillomata.

Parovarian cysts are almost invariably unilocular. Only a few cases have been reported in which two or more cavities were present.

The cysts are of small size, not often exceeding that of a child's head. They may, however, attain large dimensions and contain several quarts of fluid.

Parovarian cysts are of very slow growth, and refill but slowly after tapping or rupture. On account of the thinness of the cyst-walls, these cysts seem especially liable to the accident of rupture. Unless the cyst be papillomatous, the bland, unirritating fluid is readily absorbed by the peritoneum, and the cyst may remain quiescent for a long period.

Cysts of the parovarium occur most frequently during the period of active sexual life. Unlike dermoids and cysts of the oöphoron, they are unknown in childhood.

Cysts of the parovarium are much less common than cysts of the oöphoron and paroöphoron. In 284 tumors of the ovary and parovarium operated upon by Olshausen, about II per cent. originated in the parovarium.

Some authorities maintain that in rare instances dermoid cysts may arise from the parovarium.

The symptoms of parovarian cysts resemble those of ovarian cysts of similar development. On account of the intra-ligamentous development of the tumor, pressuresymptoms may appear early. The cyst is of such slow growth that the simple parovarian cyst may exist for a long time without giving any trouble whatever. The slow growth is the only clinical feature that would enable one to make a diagnosis between parovarian and ovarian cyst.

COMPARISON OF OÖPHORITIC, PAROÖPHORITIC, AND PAROVARIAN CYSTS.

The chief characteristic features of the large cysts of the ovary and the parovarium-the glandular cyst, the

paroöphoritic cyst, and the parovarian cyst-may be tabulated for comparison as follows:

FIG. 169.-Section, perpendicular to the long axis of the Fallopian tube, showing the relation of a paroöphoritic cyst to the oöphoron and the peritoneum of the broad ligament.

velopment; no peritoneal investment. Ovary destroyed early in the course of the disease. Cyst multilocular. Fluid contents thick, colored; specific gravity greater than 1010.

Tumor of rapid growth.

Usually unilateral.

Fallopian tube distinct from tumor, and not much, if any, elongated.

Paroöphoritic Cyst.-Often extra-peritoneal in development, in which case there is a detachable peritoneal investment.

Oöphoron not at first involved by the growth.
Unilocular.

Fluid contents less thick and viscid than in oöphoritic cyst.

Interior filled with papillomata.

Tumor usually of slower

growth than the oöphoritic

PAROVARIUM
TUBES

FIG. 170.-Section, perpendicular to the long axis of the Fallopian tube, showing the relation of a parovarian cyst to the ovary, the tube, and the peritoneum of the broad ligament.

Wall thin. Fluid contents watery, opalescent; specific gravity below 1010.

May or may not have papillomata in interior.

Tumor of very slow growth.

Usually unilateral.

Fallopian tube much elongated and stretched immediately over the surface of the cyst.

CHAPTER XXXI.

NATURAL HISTORY AND TREATMENT OF OVARIAN CYSTS.

IN the discussion of the secondary changes, the clinical history, and the treatment of cysts, the oöphoritic, paroöphoritic, and parovarian cysts will be considered. together under the general heading of ovarian cysts.

SECONDARY CHANGES OR ACCIDENTS OF OVARIAN CYSTS.

There are various accidents which may happen to an ovarian cyst which have an important bearing on the clinical course of the disease. These accidents are: inflammation and suppuration; torsion of the pedicle; rupture of the cyst.

Inflammation and Suppuration.-Inflammation of an ovarian cyst is of very common occurrence. It seems especially liable to happen in the small cysts of pelvic growth. Ovarian dermoids are very often inflamed. The inflammation may result in but a few peritoneal adhesions between the outer surface of the cyst and some of the contiguous structures, as a loop of intestine, the bladder, the anterior abdominal wall, the omentum, etc., or the whole cyst may be universally adherent, so that its removal is rendered most difficult, and in some cases impossible.

The operator should always remember the possibility of these adhesions in removing an ovarian cyst. Its surface should be carefully examined as it is dragged slowly through the abdominal incision, in order that slight adhesions to delicate structures like the omentum and the vermiform appendix may not be recklessly or unknowingly torn.

The sources of inflammatory infection of an ovarian cyst are the intestinal tract, the urinary bladder, and the Fallopian tube. Perhaps salpingitis is the most frequent cause of such inflammation. Infection often comes from the vermiform appendix, which is frequently found adherent to the surface of the tumor.

Old adhesions usually contain blood-vessels, which may be of large size, especially if they arise from the intestine, the omentum, or the uterus. In some cases in which the tumor has become detached from the pedicle by rotation or traction the adhesions have been sufficiently vascular to maintain the vitality of the tumor.

Suppuration of ovarian cysts is sometimes seen. It was more frequent in the period when these tumors were treated by tapping, as infection occurred in this way.

Suppuration is most common in ovarian dermoids. The tumor may become adherent to surrounding structures, and may discharge its contents through the bladder, the vagina, the rectum, or the abdominal wall. A tooth thus discharged into the bladder from a suppurating dermoid has in several instances formed the nucleus of a vesical calculus.

A suppurating ovarian cyst sometimes contains gas, either from communication with the intestine or from decomposition of its contents. In such a case the usual tumor-dulness is replaced by a tympanitic note.

Torsion of the Pedicle, or Axial Rotation.-Ovarian tumors occasionally rotate upon their axes, so that the structures that form the pedicle become twisted. The severity of the symptoms that arise from this accident. depends upon the degree of compression to which the vessels of the pedicle are subjected from the torsion.

The accident is not now as common as formerly, because the tumor is, as a rule, now removed as soon as it is recognized, and many of the accidents that were described as very frequent by the older writers are avoided. The many recorded cases-chiefly of a date before our present surgical era-show that axial rotation occurred in