Small renal parenchymal neoplasms: further observations on growth.

Abstract

To determine the growTH rate and behavior of small (< or = 3.5-cm diameter) incidentally detected renal parenchymal neoplasms. Forty renal parenchymal tumors in 37 adult patients (mean age, 65.5 years) were observed with computed tomography (CT) and ultrasound for 1.75-8.5 years (mean, 3.25 years). Surgical removal was performed of 26 tumors proved and graded at pathologic examination. Fourteen tumors with CT criteria of neoplasm are being followed up. 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 grew very slowly (< or = 0.35 cm/y). No patient developed metastatic disease. Nine (24%) had multiple neoplasms. Most small, incidentally discovered, well-marginated renal parenchymal neoplasms grow slowly and are not an immediate threat to a patient's life. Watchful waiting might be appropriate instead of surgical removal, especially in patients who are elderly or may not survive surgery.