What is the diagnosis and treatment for Pheochromocytoma (a type of adrenal gland tumor)?

From the Guidelines

Pheochromocytoma should be treated with surgical removal of the tumor after medical preparation with alpha-blockers, such as doxazosin or terazosin, followed by beta-blockers if necessary, to control blood pressure and adrenergic crises, as recommended by the most recent guidelines 1. The diagnosis of pheochromocytoma involves measuring catecholamine levels in blood or urine, followed by imaging studies like CT or MRI to locate the tumor. Key points to consider in the management of pheochromocytoma include:

• The importance of alpha-blocker therapy prior to surgery to prevent catecholamine surges intraoperatively 2
• The need for lifelong monitoring after surgery due to the risk of recurrence and potential association with genetic syndromes 3
• The use of genetic testing for affected individuals and potentially their family members, especially in cases associated with genetic syndromes like Multiple Endocrine Neoplasia type 2, von Hippel-Lindau disease, or neurofibromatosis type 1 1 The most recent guidelines recommend the use of doxazosin or terazosin as alpha-blockers, followed by beta-blockers if necessary, to control blood pressure and adrenergic crises 1. Adequate fluid administration should be carefully managed to avoid profound hypotension, particularly right after tumor excision 1. It is crucial to prioritize the management of pheochromocytoma based on the most recent and highest-quality evidence to optimize patient outcomes in terms of morbidity, mortality, and quality of life.

From the FDA Drug Label

Phenoxybenzamine hydrochloride capsules are indicated in the treatment of pheochromocytoma, to control episodes of hypertension and sweating. If tachycardia is excessive, it may be necessary to use a beta-blocking agent concomitantly.

• Pheochromocytoma treatment: Phenoxybenzamine is indicated for the treatment of pheochromocytoma to control episodes of hypertension and sweating.
• Concomitant use: A beta-blocking agent may be necessary to use concomitantly if tachycardia is excessive 4.

From the Research

Definition and Overview of Pheochromocytoma

• Pheochromocytoma is a rare, mostly benign catecholamine-producing tumor of chromaffin cells of the adrenal medulla or of a paraganglion 5.
• It is an uncommon cause of secondary hypertension, but it is also a curable form of hypertension with proper treatment 6.
• The outlook for patients with pheochromocytoma is excellent if diagnosed and treated properly, but if undiagnosed or untreated, it can cause serious complications and death 6.

Clinical Manifestations

• Typical clinical manifestations of pheochromocytoma include sustained or paroxysmal hypertension, severe headaches, palpitations, and sweating resulting from hormone excess 5.
• The presentation of pheochromocytoma is highly variable and can mimic many other diseases, making it challenging to diagnose 5, 7.
• Pheochromocytoma can cause the most dramatic, life-threatening crises in all of endocrinology, characterized by severe hypertension associated with cardiac complications, hypotension, or even shock and sudden death 7.

Diagnosis

• The diagnosis of pheochromocytoma depends mainly upon the demonstration of catecholamine excess by 24-h urinary catecholamines and metanephrines or plasma metanephrines 5.
• Localization of pheochromocytoma is done by computed tomography scan and magnetic resonance imaging of the adrenal glands and abdomen, with complementary 123I-metaiodobenzylguanidine scintigraphy and 18F-dihydroxyphenylalanine-positron emission tomography available 5.
• Screening for genetic alterations is important, as approximately one out of four pheochromocytomas turn out to be hereditary entities 5.

Treatment

• Surgical removal of pheochromocytoma is the treatment of choice, with laparoscopic and adrenal sparing surgical intervention following preoperative alpha-blockade being the preferred approach 5, 8.
• Preoperative medical management aimed at blocking the effects of catecholamines is crucial to prevent hemodynamic instability during surgery 6, 9.
• For patients with inoperable, malignant, recurrent, or multicentric pheochromocytomas, chronic medical therapy is indicated in the form of alpha- and/or beta-blockade or inhibition of catecholamine synthesis with alpha-methyl-para-tyrosine 6, 8.
• The choice of alpha-blocker for preoperative treatment, such as phenoxybenzamine or doxazosin, depends on various factors, and there is no evidently superior alpha-blocker for the pretreatment of patients with pheochromocytoma 9.