[Chromophobe carcinoma of the kidney]

Chromophobe renal cell carcinoma, described in 1985 is a type of renal carcinoma which is relatively uncommon (5%). Although the majority of studies published suggest a more favourable prognosis, conclusive evidence does not exist. In this study we present the clinical and ultrastructural characteristics and particularly the prognoses of 15 patients taken from a group of 230, all of whom had been diagnosed as suffering from renal carcinoma and for which they had received surgical treatment.

230 kidneys were analysed between June 1990 and December 1997. The tissue was fixed and dyed with H-E, Hale's acid iron colloid and PAS. Two models were defined, typical and eosinophil. In 8 cases the tissue was processed in order to quantify the DNA using flow cytometry.

Of the 230 kidneys analyzed, 15 were identified as being compatible with a diagnosis of chromophobe carcinoma, representing 6.5% of the group studied whilst 73% corresponded to the typical model. The average follow-up period for the 15 patients studied was of three and a half years. Upon completion of the study, 14 out of the 15 patients were still alive and the remaining one had died from causes unrelated to his illness. The average period of survival was 43 months. The tumors had an average diameter of 7.9 cm. The nuclear grade was GII on 10 occasions (seven T2, one T3a and two T3b) and GIII on 5 (four T2, one T3a and two T3b). The study of flow cytometry showed four cases of multiploids two of aneuploids one tetraploid and one diploid.

Chromophobe renal cell carcinoma is a relatively uncommon (6.5%) type of renal carcinoma. The typical ultrastructural type is the most common (73%). The highly favourable pathologic stage (p2 73%) and the significantly low nuclear grade (66% GII) suggest that this is a tumour with a rather better prognosis, as is shown by an increased period of survival.