A modified bronchial brush is presented as a new cytologic method to improve the value of fine-needle aspiration biopsy in the diagnosis of cystic lesions of bone. Four female and six male patients ranging in age from 10 to 44 years were studied. In all cases intralesional brushing was percutaneously performed under fluoroscopic control with local anesthesia. Fine-needle aspiration biopsy preceded intralesional brushing and was performed as described elsewhere. The brush was driven into the walls and septa of an osteolytic lesion through a 14-G needle; material obtained was fixed and processed for cytological and/or histological examinations.