A Renin-Secreting Tumor

Abstract

A 23-year-old white male was referred for hypertension resistant to triple antihypertensive treatment, with hypokalemia, hyperaldosteronism and elevated levels of circulating plasma renin activity (PRA). Renal angiography and echoscans put in evidence an avascular solid mass at the midlower level of the right kidney. Renal vein catheterization with sampling of blood from the lower branches of the right renal vein showed lateralization of renin secretion from that side. After surgical exeresis, the mass (1.0 cm) was diagnosed as a renal hemangiopericytoma on the basis of light and electron microscopy. Tumor exeresis was followed by a prompt normalization of blood pressure and plasma potassium, with a decrease in PRA and aldosterone. Two months after surgery the patient was still normotensive. Circulating levels of inactive (trypsin-activable) renin were around 60% of the total pool of plasma renin, i.e. much lower than those reported in other cases of renin-secreting tumors. After surgery, inactive and active renin fell in parallel, implying that both were secreted by the tumor. Tumoral PRA responded to postural stimulation, but was unresponsive to acute converting enzyme inhibition, suggesting that sympathetic stimuli were still operative, but the negative feedback inhibition by angiotensin II on renin secretion was lost. Acute converting enzyme inhibition by captopril dropped blood pressure; however, during long-term treatment, the drug (3 × 50 mg/day) was ineffective in terms of either blood pressure normalization or relief of secondary hyperaldosteronism. Acute calcium entry blockade by nifedipine (10 mg p.o.) caused an evident blood pressure drop.

Paraneoplastic Syndromes in Patients with Urological Malignancies

“…Ureteral obstruction may cause renin secretion by a similar mechanism. Additionally, although rare, renin-secreting tumors may arise from the juxtaglomerular apparatus itself and, as expected, are associated with hyperaldosteronism and hypokalemia [43] .…”

A Very Small Juxtaglomerular Cell Tumor Preoperatively Identified by Magnetic Resonance Imaging.

“…The tumor was demonstrated as an iso-signal intensity area on Trweighted images and as a high-signal intensity area on T2-weighted images, but it showed no enhancement by Gd-DTPA. These findings are in accord with the CT finding ofa low density area without enhancement and the renal angiographic finding of a hypovascular area (4,(12)(13)(14)(15)(16)(17). By contrast, renal cell carcinomais usually demonstrated as a high-signal intensity area on T2-weighted images with inhomogenous enhancement by GdDTPAon MRI(1 8), as a high density area with enhancement by iohexol on CT (18) and as a hypervascular area on renal angiography (19).…”

Reninoma: case report and literature review

“…In our case, it is not clear that furosemide administration improved the sensitivity of the catheterization procedure. Administration of angiotensin-converting enzyme inhibitors (ACEI) has also been suggested based on the theory that JGA tumors retain a negative feedback control on renin secretion normally exerted by angiotensin II [11,21,56]. In our subject, basal PRA measurements from the renal veins did not lateralize, despite segmental venous cannulation.…”