Clinical, ultrasonographic, computed tomography and histopathological manifestations of ovarian steroid cell tumour, not otherwise specified: our experience of a rare case with female virilisation and review of the literature

Introduction. Ovarian steroid cell tumours, not otherwise specified (NOS) are rare sex cord-stromal tumours of the ovary. These tumours should be considered a cause of isosexual precocious puberty in children and virilisation in adults. Case. We report a case of 40-year-old woman with mental handicap who presented with 3 years of amenorrhea and progressive virilisation. Pelvic ultrasonography identified a 6.19 x 6.15 cm well-defined echogenic-multilobular mass arising from the left ovary. Fluid in the cul-de-sac was noted. Colour Doppler examination with endovaginal ultrasonography showed high vascularity of the tumour with low resistance to flow. A computed tomography (CT) scan of the upper and lower abdomen showed a lobular mass with diaphragms in the left adnexal structure and fluid in the cul-de-sac; no adrenal gland enlargement or additional tumour was detected. Laboratory analysis revealed increased levels of serum total testosterone. Total abdominal hysterectomy with bilateral salpingo-oophorectomy was performed. Histological examination showed a benign steroid cell tumour, NOS without evidence of necrosis, haemorrhage or invasion. The immunohistochemical study showed that the tumour cells were positive for inhibin, CD 99, Melan A and vimentin and negative to CK AE1, CK AE3, progesterone and estrogen receptors. Conclusion. Careful medical history, physical examination, laboratory serum values and imaging studies are helpful in making the pre-operative diagnosis. Steroid cell tumours, NOS are usually benign, unilateral and characterised by the composition of two similar-appearing polygonal cell types. They differ from Leydig cell tumours in the lack of crystals of Reinke in their cytoplasm.