The cysts included here form a marked contrast to the proper ovarian ones. They have no solid secreting tissue, and their contents are not colloid. They are unilocular, and they show relations to the ovary and Fallopian tube which proclaim their origin in the ala vespertilionis which lies above the ovary, and contains the parovarium. It is natural to infer that they originate in this rudimentary organ, but recently doubts have been raised as to this as the origin of all these cysts. Hence the general term cysts of the broad ligament is now more frequently in use. It is acknowledged that some of them originate in the parovarium, and, according to Doran, it is chiefly those which show papillomatous ingrowths which do so. At the same time, the general characters of all these cysts are otherwise so similar that one is led to infer a common origin, and they may be grouped together as parovarian cysts.

The cysts of the broad ligament are nearly always unilocular. They frequently grow to large dimensions, and they have a perfectly simple connective-tissue wall, without any trace of partitions.

Growing between the two folds of the broad ligament they distend the peritoneum over them, and this peritoneal covering, being loosely attached to the proper cyst-wall, can be readily separated. As it has attained to considerable thickness the peritoneal coat itself makes a distinct cyst, like the outer skin of a football. In this respect the cyst differs from the ovarian forms, in which no such layer of peritoneum is distinguishable.

From the position of these tumours, lying in the position of the parovarium between ovary and Fallopian tube (see Fig. 459, p. 1018), they stretch these structures greatly. The figure shows that a girdle is formed round this part of the broad ligament, by Fallopian tube, ovarian fimbria, ovary and ovarian ligament. This girdle remains around the cyst but is greatly elongated. The Fallopian tube is enlarged and elongated till it may measure fourteen or fifteen inches. The fimbriated extremity is flattened out and exaggerated, while the ovarian fimbria is stretched and thickened. The Ovary generally hangs from the lower part of the cyst, elongated and condensed. The ovarian ligament completes the girdle. There is thus no proper pedicle such as ovarian tumours usually have.

The contents of the cyst are usually a clear, colourless fluid, of a specific gravity not greatly exceeding 1008.

In most cases the internal surface of the cyst is smooth, but sometimes jntra-cystic papillary growth occurs, this form being sup posed to be specially parovarian. The papillomatous cysts, like the similar ones of the ovary, show malignant characters.

Rupture of these cysts is not accompanied by the inflammatory manifestations produced by the ovarian cysts. The papillomatous forms, however, may lead to secondary growths by rupture. The ruptured cysts may lie for years in the abdomen, producing little or no disturbance, and without any tendency to refill. This was so in a case observed by Gairdner and the author, and preserved in the Western Infirmary Museum.

Fig. 464. - Section of wall of dermoid cyst of ovary. A congeries of sebaceous glands with open mouths (a, a, a) occupy the wall. The cyst contained large masses of buttery material with hairs, x 20.