STUDY ON SMALL RENAL CELL CARCINOMA DIAGNOSED BY ULTRASONOGRAPHY

Sixty-seven patients underwent a resection of renal cell carcinoma in our hospital beteen July 1984 and Mar. 1989. Out of them 31 patients with small renal cell carcinoma less than 4cm in diameter were examined. The proportion of small renal cell carcinoma to all renal cell carcinoma was 36% (14 patients) in the first half period (July 1984-July 1987) and 61% (17 patients) in the last half (Aug. 1987-Mar. 1989), i. e. in total more than half of all the carcinomas. The patients diagnosed by ultrasonographic screening were 25 (80%) out of the 31 patients. The incidence of small renal cell carcinoma was 4 (0.06%) out of 6892 patients in our health check-up center and 6 (1.0%) out of 610 hemodialysis patients, and they were found by ultrasonic examination. The carcinoma was protruded from the renal contour in 24 patients (77%) and was inside the renal parenchyma (23%) in 7 patients. The carcinoma in the 24 patients was associated with the deformity of its outline. The patients with a positive IVP were 5 out of 31 patients and the carcinoma in 4 out of the 5 patients was inside the renal parenchyma. Of all patients with protrusion of to renal contour, only one patient was with a positive IVP. The above findings indicate that ultrasonic examination is a useful metod for the early diagnosis of small renal cell carcinoma.