From the Guidelines
Pheochromocytoma and paraganglioma are the primary conditions characterized by excessive catecholamine production, diagnosed by increased serum and urine levels of catecholamines, or their breakdown products metanephrines (VMA and HVA). The diagnosis of these conditions begins with biochemical testing, including 24-hour urinary metanephrines and plasma free metanephrines, which have high sensitivity 1. Positive biochemical tests should be followed by imaging studies such as CT or MRI to locate the tumor, with MIBG scans or PET imaging used for further localization if needed. Genetic testing is recommended for all patients due to the high prevalence of hereditary forms. Management primarily involves surgical resection of the tumor after proper preoperative preparation, which typically includes alpha-adrenergic blockade with phenoxybenzamine or doxazosin, followed by beta-blockers only after adequate alpha blockade 1.
Some key points to consider in the management of pheochromocytoma and paraganglioma include:
- The use of alpha-adrenergic blockers such as phenoxybenzamine, doxazosin, or terazosin to control blood pressure and prevent adrenergic crises 1
- The importance of careful anesthesia management during surgery to prevent blood pressure fluctuations 1
- The need for lifelong follow-up with periodic biochemical testing to monitor for recurrence 1
- The potential for malignant forms to require additional treatments, including radiation therapy, chemotherapy, or targeted therapies 1
It is essential to note that the diagnosis and management of pheochromocytoma and paraganglioma require a multidisciplinary approach, and patients should be managed by a team of healthcare professionals with expertise in endocrinology, surgery, and anesthesia. The goal of treatment is to reduce morbidity and mortality, and improve quality of life, by controlling blood pressure, preventing adrenergic crises, and managing related complications.
From the Research
Diagnosis of the Condition
The condition characterized by excessive production of catecholamines, such as adrenaline (epinephrine) and noradrenaline (norepinephrine), is diagnosed by increased serum and urine levels of catecholamines, or their breakdown products metanephrines (VMA and HVA) 2, 3, 4, 5, 6.
- The diagnosis depends mainly upon the demonstration of catecholamine excess by 24-h urinary catecholamines and metanephrines or plasma metanephrines 2.
- Biochemical testing for the condition should be performed not only in symptomatic subjects or in subjects with adrenal incidentaloma but also in subjects with a genetic predisposition for the condition 4.
- Measurement of plasma free metanephrines by immunoassay appears to be a useful diagnostic test in patients suspected of the condition, with a high specificity as compared with urinary catecholamines 3.
Condition Characterization
The condition is characterized by:
- Sustained or paroxysmal hypertension, severe headaches, palpitations, and sweating resulting from hormone excess 2, 4, 5.
- Catecholamine-producing tumors of the sympathetic nervous system 5.
- Various clinical symptoms, but mostly with headache, sweating, palpitations, and hypertension 4.
Management of the Condition
The management of the condition includes:
- Laparoscopic and adrenal sparing surgical intervention following preoperative alpha-blockade, which is the treatment of choice and usually curative 2.
- Catecholamine blockade with phenoxybenzamine and metyrosine to ameliorate symptoms and prevent hypertensive crisis during surgery 5.
- Radiotherapy and chemotherapy as palliative treatment options for malignant cases 2.
- Computed tomography (CT), magnetic resonance imaging (MRI), and functional imaging with [(123)I]-MIBG for tumor localization 2, 4.
- Adequate medical pre-treatment and follow-up after tumor removal due to possible recurrence 4.