An Ovarian Leydig Cell Tumour in a Postmenopausal Woman that was Missed on an Ultrasonogram: A Case Report

Abstract Background:Ovarian Leydig cell tumour (OLCT) is a rare functioning ovarian sex cord-stromal tumour (OSCST) that can cause hyperandrogenism and virilization. Its clinical and imaging features are atypical, which leads to misdiagnosis, missed diagnosis, or overtreatment.Case presentation:We report a case of OLCT in a postmenopausal woman that was missed on transvaginal ultrasound (TVS). Both enhanced pelvic computed tomography (CT) and magnetic resonance imaging (MRI) indicated a right adnexal space-occupying lesion.We present this missed-diagnosis case and review the literature on OLCT.Conclusions:When patients develop hyperandrogens, we should consider this rare disease in addition to more common causes. Contrast-enhanced ultrasound (CEUS) of the ovary could contribute to differential diagnosis when tiny tumours are not detected by imaging examinations or the diagnosis remains uncertain.