Intraoperative venous blood sampling to localize a small androgen-producing ovarian tumor

Background. Among other causes of virilization, ovarian tumors can be the cause of excessive androgen production. We report the case of a Leydig cell tumor of the ovary where diagnostic attempts to localize the source of hyperandrogenism preoperatively failed owing to relatively small tumor size. Case. A 36-year-old woman presented with clinical signs of severe virilization including progressive balding, increased hirsutism, secondary amenorrhea and enlargement of the clitoris. Extensive work-up included endocrinological tests, pelvic ultrasound, magnetic resonance imaging, chromosomal analysis, norcholesterol scintigraphy and selective venous sampling, without direct localization of the source of hyperandrogenism. Persistently high plasma testosterone prompted an explorative laparotomy. Intraoperative selective blood sampling of the ovarian veins and palpation gave evidence of a right ovarian tumor, which was then removed. Histological examination revealed the presence of a pure Leydig cell tumor. Conclusion. Exploratory laparotomy with intraoperative selective blood sampling of the ovarian veins might be a useful approach in patients without accurate preoperative localization of androgen-producing tumors of the ovaries.