[Symposium (2). Diagnosis and treatment of renal parenchymal mass. Chairmen's comments]

Although renal cell carcinoma occupies clinically the majority of renal parenchymal mass lesions, indeterminate renal masses among renal cystic lesions and benign renal tumors have been frequently found with recent advances in renal imaging modalities. Renal mass lesions to be differentiated from renal cell carcinoma were focused on in the symposium and the points discussed were divided into four categories. 1. Indeterminate renal cystic masses, especially focused on multilocular cystic lesions and renal malignant lesions associated with acquired cystic disease of the kidney (ACDK) and von Hippel Lindau disease. 2. Angiomyolipoma and oncocytoma, as representative ones among a variety of benign renal tumorous lesions. 3. How to treat small renal masses serendipitously detected by abdominal CT and/or ultrasound, radical nephrectomy or renal parenchyma-preserving operation? 4. Feasibility of percutaneous ultrasound-guided fine needle biopsy for suspicious renal mass lesions. In this symposium, the diagnosis and treatment of various renal mass lesions other than renal cell carcinoma were mainly discussed and the important points to diagnose and treat patients with renal cell carcinoma have been clarified.