Pathology of malignant nephrosclerosis with special reference to the difference between histologic manifestations of pure and exacerbated forms.

Fourteen autopsied cases of malignant nephrosclerosis were classified into 6 of pure form in which syndrome of malignant hypertension developed from the beginning of the disease, and 8 of exacerbated form with appearance of the syndrome in the course of essential hypertension. Pathohistological study of these cases elucidated the differences in histologic manifestations between pure and exacerbated forms of malignant nephrosclerosis as to which little had been known as yet. In the pure form arterioles and small arteries characteristically demonstrated acute or recent lesions such as fibrinoid necrosis and hemorrhage into intima, and intimal cellular hyperplasia of somewhat longer duration, whereas in the exacerbated form coexistence of vascular lesions of various intensities and durations, acute (fibrinoid necrosis and hemorrhage), intermediate (intimal cellular hyperplasia) to chronic (sclerosis and lamellar elastosis), and superposition of more recent vascular lesions on more advanced or older ones were noted. Superposition of vascular alterations was interpreted to be not necessarily specific for exacerbated form but histologic manifestation of recurrence which is liable to be the case more frequently in exacerbated form than in pure form in the longer course of essential hypertension or of malignant hypertension. Some other related problems were also considered and discussed.