Clinical features of renal cell carcinoma less than 25 millimeters in diameter.

Abstract

We retrospectively investigated the clinicopathological features and prognosis of patients who underwent surgical treatment at our department for renal cell carcinoma (RCC) less than 25 mm in diameter. Of the 158 patients who underwent surgical treatment between April 1975 and April 1998, 16 (17 kidney, 10.1%) were included in this study. The study included 11 men and 5 women (ratio: 2.2). The age range was 35-76 years (average: age 53). The right kidney was involved in 9, left kidney in 6 and bilateral kidneys in 1 patient. The follow-up period was 26-157 months (mean: 86 months). Thirteen tumors (81.2%) were incidental carcinomas. No patients had a tumor of rapid growing type. Radical nephrectomy was performed for 12 kidneys (70.6%), simple nephrectomy for 2 (11.8%) and partial nephrectomy for 3 (17.8%). Seven patients (43.7%) received interferon-alpha as postoperative adjuvant therapy. All tumors were pathologically classified as expansive type; 11 (64.8%) as clear cell carcinoma; 3 (17.6%) cyst-associated, and 3 (17.6%) papillary. Nine (52.9%) tumors were grade 1, and 8 (47.1%) were grade 2. Fourteen patients were pNo and V(-). The 5- and 10-year survival rates were excellent (100%). The features of small RCCs less than 25 mm were as follows: many tumors were incidental to clear cell carcinomas; all tumors were low grade, low stage and expansive type; no tumors showed acute phase reactants; and few tumors were of the solid type. Thus, the prognosis seemed to be excellent.