Endocrine Abstracts

The coexistence of pheochromocytoma and hyperreninemia secondary to renal artery stenosis, which both represent important causes of juvenile hypertension, has been reported in Literature, while association between pheochromocytoma and reninoma has never been described.

We evaluated a 24-year-old boy, which came to our attention for severe hypertension, unresponsive to anti-hypertensive polytherapy. In 1996, because of elevated calcitonin levels (180 pg/ml), he underwent total thyroidectomy with lymphadenectomy. Histology confirmed ‘medullary carcinoma pT4N+’. Laboratory evaluation excluded pheochromocytoma. Genetic testing showed RET mutation at codon 918 (exon 16), which was not documented in other family members, confirming the diagnosis of MEN2B. During follow-up, a progressive increase of urinary metanephrines and catecholamines was recorded, in absence of adrenal masses at MRI and with no clear pathological findings at MIBG. Our evaluation confirmed severe hypertension (220/140 mmHg) unresponsive to doxazosine and atenolol at high doses, with initial left ventricular dysfunction. Laboratory data showed a severe increase of urinary catecholamines (epinephrine: 27 μg/24 h, norepinephrine: 120.0 μg/24 h) and metanephrines (metanephrine: 3099 μg/24 h; normetanephrine: 1272 μg/24 h). Evaluation of other causes of hypertension revealed hyperreninemia (236 μUI/ml) with mild hyperaldosteronism, and an increase of renal artery resistance at US.

Abdominal MRI showed multiple adrenal masses (16 and 18 mm at right gland and 10 and 15 mm at left gland). In correspondence of the right kidney, a nodular lesion of 20 × 20 mm, hyperintense in T2-weighted sequences, was described. As first hypothesis, the above mentioned lesion was interpreted as renal oncocytoma. The patient underwent bilateral adrenalectomy and right nephrectomy. Histology confirmed bilateral pheochromocytoma and right reninoma, with normalization of blood pressure value. Laboratory evaluation showed a sudden reduction not only of urinary metanephrines but also of reninemia in spite of bilateral adrenalectomy without mineralocorticoid supplementation.