Does the finding of a indeterminate mass lesion in screening CT result in kidney loss and is postoperative follow-up necessary in renal encocytomas? A retrospective study

Abstract

Sixteen patients who were operated on with a preoperative diagnosis of renal tumor were diagnosed with renal oncocytoma between 1991 and 2004. The reliability of preoperative diagnosis, the role of screening CT in organ preservation and the need for follow-up for renal oncocytomas are discussed in the light of literature findings. Among 345 patients diagnosed with renal tumors in the previous 13 years, the clinical and radiological features of the 16 patients with renal oncocytomas and the results during the postoperative follow-up period were evaluated in this retrospective study. The female:male ratio was 4.3. Two of the patients complained of hematuria whereas the other 14 experienced lumbocostal pain. The mean dimensions of the tumors on CT scans were 5.7+/-2.88 cm. Central fibrous scarring existed in three patients. Two patients underwent tumor enucleation, three underwent partial nephrectomy and 11 underwent radical nephrectomy. Screening CT could not achieve a precise preoperative differential diagnosis from malignant renal mass. The organ preservation ratio was approximately 1:3 based on the radiological diagnosis. Screening CT scans showed oncocytomas with diameters greater than those reported in the literature, indicating a need for urgent nephrectomy. No recurrences, metastases or deaths due to renal oncocytoma were observed in the postoperative follow-up period (mean 6.7+/-4 years; range 1-13 years). Preoperative diagnosis of renal oncocytoma is very difficult. The postoperative follow-up period in our series was 13 years, which is significantly longer than the duration proposed in the literature.