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 × 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.