in the coagulum. There is not the typical double layer of Langhans. The myxomatous stroma characteristic of such early chorion is, however, well retained. In the sections taken through the central portion of the ovary, the chorionic villi are more abundant and better preserved. Several groups of these Groups of chorionic villi. Mature Grafian groups of large pigmented cells with perfectly round and centrally situated nuclei that resemble strongly lutein cells. The central mass consists of masses of red blood cells and fibrin. Some of the sections, particularly those through the rough protruding area, show few more or less degenerated villi embedded Ovarian capsule. FIG. 3.-Section taken through (b) Fig 2. At one area of the surface of the ovary there are several collections of large polygonal and fusiform pale cells with rather small round and oval nuclei (Figs. 2, 6 and 7). These present the ap may be seen at the margin of the coagulum underlying the typical ovarian stroma (Fig. 3 and 4), while other groups are variously situated within the coagulum. FIG. 4. Section taken through the ovary near the hilus. (d) Fig. 1. appearance of decidua, resembling the type seen in the premenstrual uterine mucosa and, in some parts, true decidua. Lining the space that separates the two groups is a single layer of endothelial cells (peritoneum). The tube on the left side showed no evidence of pregnancy nor any decidual reaction. The excised portion of the right ovary showed several cystic follicles, edema of the stroma with a moderate infiltration of leukocytes, and theca-lutein proliferation of one of the follicles. No decidual reaction whatever was noted. Postoperative Course. We waited two weeks after the operation to note if the patient would spontaneously pass a decidual cast. This did not occur. In view of the irregular menstrual history and the possibility of a uterine abortion, she was curetted. Very little tissue was obtained. Microscopic examination of the scrapings showed a somewhat infiltrated stroma in which a few FIG. 6. -Central group of chorionic villi. From Fig. 3. glands were embedded. There were no evidences either of pregnancy or even of a decidual reaction in these curettings. This case, therefore, satisfies all the criteria of a primary ovaian pregnancy which we mentioned. In the strictest sense this case can be regarded as an ovarian abortion. Unfortunately the mole, which I found lying free in the pouch of Douglas, went astray, and could not therefore be examined. The Incidence of Ovarian Pregnancy.-Since Norris' report of nineteen cases, in August, 1909 (Surgery. Genecology and Obstetrics) the only case that has been added to the literature up Supposed cases of to the present date is that by A. W. W. Lea. ovarian pregnancy have been reported by other observers, but owing to inconclusive microscopical proof, these cannot be admitted. My case would, therefore, make the twenty-first on record. This estimate, however, is a conservative one. With more precise laboratory examinations the cases will probably increase in frequency. As compared to tubal pregnancy, the incidence of ovarian gestation will nevertheless continue to be small. The interest that ovarian pregnancy bears is more a histological than a clinical one. The mere fact that it occurs is proof against the contention "that pregnancy can take place only on portions FIG. 7.-Showing decidual tubercles separated by a narrow cuff lined with low flat cells. From (a) Fig. 2. of the Müllerian duct derivatives." The cells lining the Graafian follicle are apparently capable of serving as a fertile soil for the embedding of the impregnated ovum. The Etiology of Ovarian Pregnancy.-Nothing is definitely known as to why ovarian pregnancy occurs. Impregnation must be assumed to have taken place within the follicle. The conditions that favor or bring about this anomalous conception are still obscure. The causes can in all probability be ascribed chiefly to maternal peculiarities. Among the maternal causes we may assume that the ovum has not been discharged into the peritoneal cavity though rupture of the follicle has taken place. This may be due to: a. The rupture is insufficient for the escape of a large ovum; b. The ovum may remain embedded in its discus proligerous; c. The follicle may have been cystic; and d. According to Leopold, a centrally situated follicle discharges into a more superficial one which then becomes the pregnant follicle. |