Endocrine Abstracts

The evaluation and treatment of pheochromocytoma and primary aldosteronism have evolved dramatically since these two forms of endocrine hypertension were first detected and treated in 1926 and 1954, respectively. We will review the challenges that surrounded the management of the prismatic cases of these two disorders and the advances that have occurred since the initial descriptions.

For example, the biochemical testing for pheochromocytomas has progressed from histamine-stimulation tests to phentolamine suppression tests, radioenzymatic assays for catecholamines, clonidine suppression tests, fluorometric assays for total metanephrines and vanillymandelic acid, high pressure liquid chromatography for fractionated catecholamines and metanephrines, and, most recently, tandem mass spectrometry assays for plasma and urine fractionated metanephrines. Localization of catecholamine-secreting tumors has progressed from exploratory laparotomy to intravenous urograms, body computed tomography, ¹³¹I-metaiodobenzylguanidine (MIBG) scintigraphy, body magnetic resonance imaging, ¹¹¹In-DTPA-pentetreotide scintigraphy, ¹²³I-MIBG scintigraphy with single photon emission computed tomographic (SPECT) images, and positron emission tomography (PET) scanning with ¹⁸F-fluorodeoxyglucose (FDG) or ¹¹C-hydroxyephedrine or 6-[¹⁸F]fluorodopamine. Approximately 15–20% of patients with catecholamine-secreting tumors have disease-causing germline mutations. Genetic testing is now available for at least six forms of hereditary catecholamine-secreting tumors.

The biochemical testing for primary aldosteronism has progressed from bioassays to detect mineralocorticoid effect to radioimmunoassays for aldosterone, enzyme assays for plasma renin activity, renin mass measurement assays, and tandem mass spectrometry assays for aldosterone. Localization of aldosterone-producing adenomas has progressed from adrenal venous sampling to iodocholesterol scintigraphy to posture stimulation test, body computed tomography, measurements of aldosterone precursors (e.g. 18-hydroxycorticosterone), and back to adrenal venous sampling. Genetic testing in now available for the rare glucocorticoid remediable aldosteronism.

The surgical management for adrenal-dependent hypertension has also advanced from open laparotomy (five night hospital stay and 4–6 weeks recovery) to laparoscopic adrenalectomy (one night hospital stay and 1 week recovery).

With these remarkable advances in the diagnosis and treatment of adrenal-dependent hypertension that have occurred over the past five decades, one can only wonder what medical advances await this field in the coming years.

Generously supported by the Clinical Endocrinology Trust.