Catecholamine-secreting tumours occur either in the adrenal medulla (phaeochromocytomas (PCs), 85%) or the sympathetic paravertebral ganglia of the thorax, abdomen, and pelvis and the organ of Zuckerkandl (paragangliomas, (PGLs) 15%). PC/PGLs present in one of four ways: i) with symptoms and/or signs of catecholamine excess; ii) with symptoms and/or signs of local tumour mass; iii) as an incidental finding on an imaging study for unrelated purpose and iv) after genetic testing in context of familial disease. Clinical features of catecholamine excess include hypertension, headache, sweating, palpitations, and apprehension. These symptoms may come in paroxysms lasting for minutes or hours, with variable frequency. Clinical examination may reveal hypertension (although absent in 10–20% cases, and paroxysmal in 30%), pallor, hyperhidrosis and tremor. Rarely, patients may present with catecholaminergic ‘crisis’ accompanied by acute cardiomyopathy and severe hypertension (but sometimes with shock), and/or multiorgan failure, lactic acidosis, encephalopathy, fever and hyperglycaemia. In such cases, precipitating factors may be present including recent use of dopamine D2 agonists (e.g. metoclopramide), corticosteroids, beta-blockers or anaesthesia. PGL of the urinary bladder is associated with catcholaminergic symptoms that are provoked by micturition, and may also be associated with painless haematuria.
“Silent” PC presents unique challenges in recognition and treatment. The prevalence of PC in incidentally discovered adrenal lesions is ~5%. Specific imaging features will often help identify an underlying PC. Plasma free metanephrines or urinary fractionated metanephrines are typically elevated.
Since PC/PGLs are associated with heritable syndromes in ~25% cases, thorough history (especially family history) and physical examination is essential in all cases for clues that might suggest VHL, NF1, MEN2, or hereditary paraganglioma syndromes.