Hypovascular renal tumors: an aggressive diagnostic approach required.

The value of a fine needle aspiration biopsy for confirmation of malignancy is demonstrated in 3 cases of angiographically hypovascular renal tumors. In 2 cases ultrasound examination suggested solid lesions but in 1 case it was predominantly sonolucent. Reliable documentation in the literature indicates that the risk of spreading tumor cells and, hence, of decreasing the survival rate is negligible.