SMALL RENAL PARENCHYMAL NEOPLASMS - FURTHER OBSERVATIONS ON GROWTH

PURPOSE: To determine the growth rate and behavior of small (less than or equal to 3.5-cm diameter) incidentally detected renal parenchymal neoplasms. MATERIALS AND METHODS: Forty renal parenchymal tumors in 37 adult patients (mean age, 65.5 years) were observed with computed tom ography (CT) and ultrasound for 1.75-8.5 years (mean, 3.25 years). Sur gical removal was performed of 26 tumors proved and graded at patholog ic examination. Fourteen tumors with CT criteria of neoplasm are being followed up. RESULTS: The overall growth rate of neoplasms was 0-1.1 cm/y (mean, 0.36 cm/y). Thirty tumors grew 0.5 cm/y or less and 19 gre w very slowly (less than or equal to 0.35 cm/y). No patient developed metastatic disease. Nine (24%) had multiple neoplasms. CONCLUSION: Mos t small, incidentally discovered, well-marginated renal parenchymal ne oplasms grow slowly and are not an immediate threat to a patient's lif e. Watchful waiting might be appropriate instead of surgical removal, especially in patients who are elderly or may not survive surgery.