Fine needle aspiration using improved agar microbiopsy is highly concordant with renal mass final diagnosis and subclassification.

Purpose: Computerized tomography and ultrasound are usually sufficient for preoperative evaluation of renal masses greater than 5 cm. For renal masses less than 5 cm additional histological evaluation could improve diagnosis and treatment decisions. We investigated the concordance between an improved agar microbiopsy technique and conventional cytology for diagnosing renal tumors.