Fast Intraoperative Testosterone Assay Confirms the Location of an Ovarian Virilizing Tumor in a Young Girl

The detection of testosterone-producing ovarian tumors in childhood and adolescence by imaging techniques only can be difficult because of the tumors' radiological structure and sometimes diminutive size. We describe an 11.5-year-old girl with a 9-month history of voice deepening, mild hirsutism, minor acne, increased growth velocity, weight gain, and clit-oromegaly. Laboratory investigation revealed an extremely elevated serum testosterone level without any additional endocrine abnormalities. Abdominal ultrasound and MRI showed a sparsely noticeable solid mass in the center of the right ovary. At laparotomy, blood was selectively drawn from the right and the left ovarian veins. Rapid testosterone measurement revealed a 70-fold higher testosterone concentration in the right ovarian vein within 45 min. Based on this finding, a right salpingo-oophorectomy was performed. The patient's postoperative testosterone level declined within 24 h. The histopathological diagnosis was Leydig cell tumor. In conclusion, the implementation of a fast intraoperative testosterone assay enabled the localization and curative therapy of a Leydig cell tumor. This technique seems to be a good alternative to preoperative selective venous blood sampling when body imaging does not unveil the tumor's site.