Combined intrauterine and ovarian pregnancy mimicking ovarian malignant tumor: imaging findings.

Abstract

In a 41 -year-old para 3 gravida 4 woman an adnexal mass was palpable on routine checkup in the 8th week of gestation. On followup, the mass was found to have enlarged rapidly. The woman complained of increasing abdominal pain, loss of weight, and vomiting. On admission in the 11th week of gestation, she was cachectic and anemic, with hen abdomen distended and tender. Elevated serum levels of carcinoembryogenic antigen 125 (CA 125) supported the diagnosis of an ovarian malignant tumor during pregnancy. Endovaginal sonography and colon Doppler examination showed the intrauterine pregnancy intact. A large mass was found oniginating from the left ovary (Fig. iA). Small amounts of free fluid were also seen. The intact early pregnancy suggested the use of MR rather than CT for preoperative staging of the suspected ovarian cancer (Fig. 1B-D). Although no evidence ofteratogenicity exists to date, the use of gadopentetate dimeglumine is not routinely recommended in pregnant women, so we preferred not to use contrast material in this case. Because of its inhomogeneous architecture and its heterogeneous signal intensity pattern indicating bleeding within the mass, and the presence of hemorrhagic ascites and bowel obstruction, the diagnosis of a malignant ovarian tumor was suggested. Laparotomy was done 2 days later. A conglomerate tumor, mainly consisting of a large hematoma, was found to extend from the left ovary to the sigmoid colon and the pelvic wall. Multiple fnozen sections from solid areas of the mass indicated placental structures with hemorrhage. Small-bowel obstruction was found to be due to multipIe adhesions of bowel loops in the left pelvic region. Histologic and histochemical workup of the resected tumor showed a large, partly organized blood clot surrounded by placental (trophoblast) tissue originating from ovarian stroma. The intact trophoblast cells showed a high activity of the beta subunit of human chorionic gonadotropin (13-HCG). No fetal structures were detected. Both the ectopic and the intrauterine pregnancy seemed to originate from the same menstrual cycle. This is supported by the fact that a preexisting 13-HCG-producing trophoblast (either ectopic or orthotopic) would have effectively prevented a second ovulation. Accordingly, a final diagnosis of double-ovum pregnancy with orthotopic and ectopic ovarian nidation was established. Although the embryoblast ofthe ovarian gestation must have died during early pregnancy-possibly due to malnutrition-there still was vital trophoblast tissue with considerable production of (3-HCG. The clinically apparent tumor growth had been caused by extensive hemorrhage into the ectopic pregnancy.