Renomedullary interstitial cell lesions and hypertension

Persistent Hypotension Associated with Hypermedullipinemia: A New Syndrome

A new syndrome is described in a patient with advanced renal insufficiency. This consists of severe and persistent hypotension causing weakness but associated with a clear mental status. Also present is evidence for decreased vascular reactivity. The hypotension was not orthostatic. The hypotension was associated with a circulating vasodepressor substance having the characteristics of medullipin 1. The medullipin appears to have been derived from the remaining right kidney. Hypotension existed despite the presence of major prohypertensive mechanisms, including an endstage kidney, hyperreninemia and hyperaldosteronemia. It is likely that hypotension due to hypermedullipinemia is an entity occurring in the human being.

Case of renal medullary fibroma

An unusual case of renal medullary fibroma accompanied by gross hematuria is reported. This is the eleventh reported case of this disease producing clinical symptoms.

Hypertension due to a renin-secreting tumour localised by segmental renal vein sampling

An 18-year-old female was found to be hypertensive on routine medical examination. Further investigation disclosed persistent hypokalaemia and elevated plasma renin activity in peripheral venous blood. Segmental renal vein sampling with assay of blood samples located the source of excess renin secretion in the lower mid-zone of the left kidney. This localization was not confirmed by either angiography or by palpation of the exposed kidney before nephrectomy but macroscopic examination of the freshly sectioned kidney revealed a small tumour in the region suggested by renal vein sampling. The tumour had the morphologic pattern fo an haemangiopericytoma with abundant ultrastructural specific granules and very high renin activity by tissue assay. Plasma renin activity fell precipitously after nephrectomy and remained very low for the first week. Although the immediate post-operative blood pressure fell to normal, hypertension recurred temporarily and was associated with elevated plasma aldosteron, producing a syndrome similar to primary aldosteronism. All variables returned to normal without specific therapy and hypertension has not subsequently recurred.