[Mixed epithelial and stromal tumour of the kidney]

The authors report the case of a patient with mixed epithelial and stromal tumour, a rare, recently described entity, as only 40 cases have been reported, mixed epithelial and stromal tumours are essentially observed in women during the perimenopausal period with a history of treatment with oestrogen-progestogens or gynaecological surgery. No clinical or radiological arguments can differentiate these tumours from other renal tumours. Histological examination reveals a tumour with an epithelial component and a stromal component presenting the characteristics of ovarian stroma and expressing oestrogen and progesterone receptors. The prognosis of these tumours is usually very favourable, although caution is advised in view of the limited number of published cases and a recent report of a malignant case.