Clear cell renal carcinoma: a distinct entity, based on a series of 35 cases.

Clear cell renal carcinoma: a distinct entity, based on a series of 35 case s. Objective:To describe the clinical and histological characteristics and natural history of clear cell renal carcinoma. Patients and Methods: The case files of 35 patients (22 men and 13 women, w ith a mean age of 58 +/- 13.8 pears) operated for clear cell renal carcinom a were reviewed. The circumstances of diagnosis and the histological featur es of the rumour were analysed. The outcome of the patients was studied wit h a mean follow-up of 70 +/- 20.2 months. Results: The diagnosis,vas incidental in 66% of cases. The macroscopic appe arance of the tumour was characteristic: homogeneous and beige or white col our: On light microscopy, tumours were composed of variable proportions of clear cells and eosinophilic cells. The were classified as 15 predominantly eosinophilic tumours (43%), 9 predominantly clear cell rumours (26%) and I I tumours composed of equal number of clear cells and eosinophilic cells (3 1%). Nuclei were irregular and indented Hale stain was positive in every ca se. The majority of rumours M ere confined to the kidney (T1: 65% and T2: 2 9%) with a low nuclear grade (91% of groups I and 2). No patient developed local recurrence or metastasis during follow-up. The overall 5-year surviva l rate tc Ns 92%. No death related to the disease was reported Conclusion: The histological diagnosis of clear cell renal cancer is now ea sy and can be suggested even on macroscopic examination of the operative sp ecimen. This tumor appears to have a good prognosis, as it is usually confi rmed to the kidney with a low nuclear grade.