Ovarian sex cord tumor with annular tubules in a woman with premature ovarian failure

Abstract Objective: To report a case of premature ovarian failure (POF) associated with an ovarian sex cord tumor with annular tubules. Design: Case report. Setting: Reproductive endocrinology unit in a tertiary academic center. Patient(s): A 20-year-old woman with POF. Intervention(s): Biopsy of the rudimentary ovary by laparoscopy. Main Outcome Measure(s): Protocol for POF investigation and histological study of the ovarian sample. Result(s): An ovarian sex cord tumor with annular tubules was detected in the rudimentary right ovary. Conclusion(s): The rare ovarian sex cord tumor with annular tubules, which may be hormonally active, was detected in a case of POF.