The ovary and broad ligament are very frequently the seats of cystic tumours, which sometimes attain vast dimensions.

The origin and mutual relations of the various forms are not completely disentangled, but a knowledge of the anatomical conditions is necessary as a preliminary.

The ovary lies at the back of the broad ligament. It is free on its two flatter surfaces and along its convex posterior border, but is attached to the broad ligament by its anterior border, which presents a deep groove or hilum by which the vessels enter. The ovary is attached to the uterus by a dense Ligament (see Fig. 459) and to the Fallopian tube by the Ovarian fimbria of that tube (see figure). It will thus be seen, as shown in the figure, that the ovarian ligament, ovary, and ovarian fimbria, as it were, circumscribe a portion of the broad ligament, which is bounded above by the Fallopian tube. This part, which is called the Ala vespertilionis or bat's wing, is of consequence as it contains the parovarium and also because it frequently comes into evidence in ovarian tumours.

The parovarium, which is the remains of the Wolffian body, is usually easily made out. It lies between the two folds of peritoneum in the ala vespertilionis. It is readily seen in most normal subjects, by holding the parts up against the light. It then appears, as in Fig. 459, po, that the organ is composed of a transverse tube or duct, and of a number of vertical tubes, 8 or 10 of which are usually well-developed. The transverse tube is the duct of Gartner, and it has been traced inwards to the wall of the uterus and onwards to end in the urethra. This tube frequently ends distally in a small pedunculated cyst (h in figure).

Diagrammatic view of uterus and appendages, po, parovarium; od, Fallopian tube.

Fig. 459. - Diagrammatic view of uterus and appendages, po, parovarium; od, Fallopian tube; fi, its fimbriated extremity; o, ovary, with the ovarium fimbria to the right proceeding to the fimbriated extremity, and a ligament to the left attaching it to the uterus near the origin of the Fallopian tube. (Quain).

The vertical tubes of the parovarium pass towards the hilum of the ovary, and they partly enter into the formation of the ovary, so that some authors describe a medullary part of this organ next the hilum and containing these Wolffian structures, and a peripheral or cortical portion containing the ova.

It follows from these anatomical relations that a tumour of the ovary proper will generally grow into the peritoneum, hanging free with a narrow pedicle. On the other hand, one arising in the parovarium or in the substance of the broad ligament, being subperitoneal in its origin, will expand the broad ligament and be seldom pedunculated.