RESUMO
AIM: To evaluate frequency of renin detection in chromophobe renal cell carcinoma, and if this expression was associated to systemic high blood pressure. MATERIAL AND METHODS: A descriptive retrospective study. All the cases with confirmed diagnosis of chromophobe carcinoma and resected between 1990 and 2004 were included in our study: 31 cases from 31 patients. Immunohistochemistry was carried out on sections from the paraffin-embedded tissue using a monoclonal antiserum. Patient blood pressure before and after neoplasm resection was registered from clinical histories. We compared frequencies of hypertension in cases with and without expression of renin (Fisher's text or chi(2) as appropriate) and evolution of HTA after tumour resection. RESULTS: We found that 10 of 31 tumors (32.3%) contained immunoreactivity for renin; this staining was diffuse in 6 cases and focal in the other 4. Systemic hypertension was detected in 6 of 10 (60.0%) patients with renin expression and in 6 of 21 (28.6%) patients without renin immunolabeling (p=0.13). After tumor resection none patient with renin expression and high blood pressure showed remission of the hypertension. CONCLUSION: Renin is frequently expressed in chromophobe renal cell carcinoma, but this renin appears clinically inactive. More studies will be necessary to know implications of this feature on clinical presentation, diagnosis or pathogenesis.