With respect to phaeochromocytoma:
a) What is the usual mode of clinical presentation? (30% marks)
b) What biochemical tests and imaging can be performed to make the diagnosis?
c) Outline the key features of preoperative preparation and postoperative management.
a) What is the usual mode of clinical presentation
Symptomatic patient. Classic triad of symptoms consists of episodic headache, sweating, and tachycardia. Sustained or paroxysmal hypertension and less commonly visual blurring, papilledema, weight loss, polyuria, polydipsia and cardiomyopathy.
Incidental adrenal mass
Family history in patients with familial disease.
b) What biochemical tests and imaging can be performed to make the diagnosis
24-hour urinary excretion of catecholamines and total metanephrines.
Plasma fractionated catecholamines (dopamine, norepinephrine, and epinephrine) and fractionated metanephrines (metanephrine and normetanephrine)
CT or MRI of abdomen and pelvis Scintigraphy and PET scanning
c) Outline the key features of preoperative preparation and postoperative management
Combined alpha and beta-adrenergic blockade
Calcium channel blockers
Metyrosine which inhibits catecholamine synthesis
Post-operative management in ICU
Hypertensive crises or arrhythmias common complications
Patients who have bilateral adrenalectomies will require steroid cover
"What is the usual mode of clinical presentation", they ask. Depending on what one means by mode, the answer may be "private car, ambulance, or fixed wing aircraft". Judging by the college answer, what they wanted was something about the clinical manifestations of a symptomatic patient, as well as the various ways in which an incidental phaechromocytoma may be discovered. About 10% of them are found on random CTs and MRIs which are done for other reasons (Kudva et al, 1999).
- Paroxysmal or sustained hypertension
- Palpitations and tachycardia
- Chest pain and myocardial infarction
- Symptoms and signs of heart failure
- Acute pulmonary oedema
There is also a possibility that one has their phaemochromocytoma diagnosed in the course of intentional phaeochromocytoma screening, because of some some sot of familial predisposition. There is also a well-known association between thyroid carcinoma and phaeochromocytoma - investigators in 1961 concluded that "the incidence of carcinoma of the thyroid gland is increased far beyond expectation based on chance concurrence".
What biochemical tests and imaging can be performed to make the diagnosis?
Investigations for phaeochromocytoma should include the following:
- Tests for catecholamines and their metabolites
- Urinary catecholamines
- Plasma catecholamines
- Urinary fractionated metanephrines
- Plasma free metanephrines (these appear to be the best single investigation)
- Urinary vanillylmandelic acid
- Clonidine suppression test
- In patients with phaeochromocytoma, serum catecholamine levels will not decrease in response to clonidine.
Overall, one's management should be guided by some sort of interational consensus guidelines, which take the following shape:
Outline the key features of preoperative preparation and postoperative management
- Control of hypertension
- Rapidly acting α-1 antagonist: phentolamine
- Slowly acting non-competitive α-1 antagonist: phenoxybenzamine
- β-antagonist (after α-antagonist)
- Maintenance of circulating volume in the face of vasodilation:
- IV fluid replacement
- Control of AF
- Verapimil, diltiazem, or amiodarone
- Assessment of myocardial damage
- CK and troponin
- Radionuclide imaging - the test of choice currently is 123I-labeled meta-iodobenzylguanide scintigraphy.
Kudva, Yogish C., et al. "Adrenal incidentaloma: an important component of the clinical presentation spectrum of benign sporadic adrenal pheochromocytoma." The endocrinologist9.2 (1999): 77-80.
Goldstein, David S., Graeme Eisenhofer, and Irwin J. Kopin. "Sources and significance of plasma levels of catechols and their metabolites in humans."Journal of Pharmacology and Experimental Therapeutics 305.3 (2003): 800-811.
Sardesai, Suhrud H., et al. "Phaeochromocytoma and catecholamine induced cardiomyopathy presenting as heart failure." British heart journal 63.4 (1990): 234-237.
Lenders, Jacques WM, et al. "Biochemical diagnosis of pheochromocytoma: which test is best?." Jama 287.11 (2002): 1427-1434.
Russell, Walter John, et al. "The preoperative management of phaeochromocytoma." Anaesthesia and intensive care 26.2 (1998): 196-200.
Eschen, Ole, et al. "Pheochromocytoma, a rare cause of acute cardiogenic shock." Clinical research in cardiology 96.4 (2007): 232-235.
Li, Ling, et al. "Transthoracic Echocardiographic Features of Cardiac Pheochromocytoma: A Single‐Institution Experience." Echocardiography 29.2 (2012): 153-157.
Leissner, Kay B., et al. "Catecholamine-induced cardiomyopathy and Pheochromocytoma." Anesthesia & Analgesia 107.2 (2008): 410-412.
Sanchez-Recalde, Angel, et al. "Pheochromocytoma-related cardiomyopathy inverted Takotsubo contractile pattern." Circulation 113.17 (2006): e738-e739.
Sipple, John H. "The association of pheochromocytoma with carcinoma of the thyroid gland." The American Journal of Medicine 31.1 (1961): 163-166.
Pacak, Karel, et al. "Pheochromocytoma: recommendations for clinical practice from the First International Symposium." Nature clinical practice Endocrinology & metabolism 3.2 (2007): 92-102.
Reisch, Nicole, et al. "Pheochromocytoma: presentation, diagnosis and treatment." Journal of hypertension 24.12 (2006): 2331-2339.
Cohen, C. D., and D. M. Dent. "Phaeochromocytoma and acute cardiovascular death (with special reference to myocardial infarction)." Postgraduate medical journal 60.700 (1984): 111-115.
Liao, Wei-Ber, et al. "Cardiovascular manifestations of pheochromocytoma."The American journal of emergency medicine 18.5 (2000): 622-625.
Jiang, Lei, et al. "123I-labeled metaiodobenzylguanidine for diagnosis of neuroendocrine tumors." Reports in Medical Imaging 2 (2009): 79-89.