Renin expression in renal oncocytomas

Abstract

Introduction: Renal cell tumors have been shown to be associated with secretory products, including renin. Our aim was to investigate the frequency of renin expression in an infrequent kind of epithelial renal neoplasm, the oncocytoma, and to find out if this expression was associated to systemic high blood pressure.

Methods: We examined a series of 13 tumors (from 13 patients) using a monoclonal antiserum to detect the hormone by immunohistochemistry (IHC), and its association with hypertension. IHC features were evaluated. Systemic blood pressure information before and after neoplasm resection was obtained from clinical charts.

Results: We found that eight of the 13 tumors (61.5%) were immunoreactive for renin, all of them with diffuse staining. In three cases the immunolabeling was paranuclear dot-like and in three more it was found in the apical portion of the cytoplasm. Systemic hypertension was detected in three of the eight (37.5%) patients with renin expression and in three of the five (60.0%) without it (p = 0.59). After tumor resection none of the patients with renin expression and high blood pressure showed remission of the hypertension.

Conclusion: Renin is frequently expressed in renal oncocytomas, but it appears to be clinically inactive. More studies will be necessary in order to define the implications of this expression on clinical presentation, diagnosis and histogenesis.