Significance of ultrasonography in detection of incidental renal cell carcinoma

Objective: Incidental detection of renal cell carcinoma (RCC) has increased significantly in recent years because of widespread use of abdominal imaging, especially abdominal ultrasonography. The aim of this study was to evaluate the effect of abdominal ultrasonography in detection of RCC and to determine the incidence of RCC in asymptomatic population.

Materials and methods: Between January 2007 and April 2009, 12 patients with renal mass among 13,260 adults for whom the abdominal ultrasonography was performed at the our hospital were included in the study. Radical nephrectomy was performed in all of these 12 patients. After surgery, all resected nephrectomy materials were evaluated histopathologically and classified as malign or benign lesions. Incidence of RCC was calculated as the ratio histopathologically confirmed RCC to the total number of ultrasonography in asymptomatic patients (11/13,260; 0.82%).

Results: Of the 13,260 patients who had abdominal ultrasonographic examination (mean age 43.8 years; range 16-87 years), 12 (0.9%) had renal mass, 11 (0.82%) had RCC, and 1 had angiomyolipoma. According to UICC-TNM classification, of the 11 patients with histopathological diagnosis of RCC, 8 (72.7%) belonged to T1 stage and 3 to T2 stage. The tumor size ranged between 1.3 cm and 7.7 cm (mean 4.9 cm). Tumor size was <4 cm (T1a) in 5 patients, 4-7 cm in 3 patients (T1b), and 7-8 cm (T2) in 3 patients. Postoperative follow-up period was 3-47 months (mean 23.4 months) and all patients were alive at the end of follow-up.

Conclusion: Abdominal ultrasonography is the most effective method for early diagnosis of RCC in asymptomatic patient. More frequent and widespread use of abdominal ultrasonography should be recommended for early diagnosis of RCC, effective treatment, and good prognosis in asymptomatic patients.