An ultrastructural analysis of renal arterioles in benign and malignant essential hypertensions.

Renal arterioles from five patients with benign essential hypertension (BH) and four patients with malignant essential hypertension (MH) were studied using electron microscopy (EM). This study suggests a concept of different pathogenetic mechanism for renal vascular (arteriolar) lesions in BH and MH (i.e., benign and malignant nephrosclerosis, respectively) and does not support the idea of progression of benign nephrosclerosis to malignant nephrosclerosis. The EM technique has proven to be important in demonstrating specific changes characteristic of severe (or malignant) hypertension in the early stage in patients without clinical manifestation of MH, thus predicting a possibility of progressive histological change and clinical deterioration. This technique has clarified the light microscopy appearance of hyaline which continues to be an intriguing feature in the study of renal pathology.