Hilus cell pathology and hirsutism.

Hilus cell abnormalities are uncommon causes of hirsutism with virilization. Although hilus cell tumours have been well described, hilus cell hyperplasia is rare and is poorly defined clinically. We describe three cases of hilus cell hyperplasia and compare them with a case of hilus cell tumour. Both pathologies were associated with increased testosterone and oestradiol secretion. Suppression of testosterone to the 'normal range' in response to exogenous oestrogen was seen only in the cases with hyperplasia; only partial responsiveness was seen in the case with hilus cell tumour. Bilateral oophorectomy offers the potential for cure for both hilus cell hyperplasia and tumour.