[Solitary fibrous tumor of the kidney].

The diagnosis of solitary fibrous tumour, usually a benign lesion, is rarely suggested in a case of renal mass due to the rarity of these lesions. The authors report a case of a very large hilar mass in a 35-year-old man. Histological examination was performed on the operative specimen, as preliminary CT-guided needle biopsy was non-diagnostic. The diagnosis of primary spindle cell tumour was confirmed by immunohistochemical analysis. Independently of the size of this tumour and its intimate relations with the hilar region, large surgical resection should be performed due to the possible presence of malignant contingents and the risk of local recurrence or metastatic spread.