Endocrine Abstracts

Introduction: Pheochromocytoma is a rare tumour of the adrenal glands. Pheochromocytomas clinical manifestations result from production of excessive catecholamines levels. Catecholamines are chemical messengers crucial for various psychological processes including stress regulation and cardiovascular function. The incidence of pheochromocytoma is at 0.2-0.8 per 100 000 persons.

Case presentation: We present a case of 42-year-old female from our centre under investigation for left adrenal incidentaloma consisting of Over Night Dexamethasone Suppression Test (ODST), Renin-Aldosterone Ratio and Plasma Metanephrines. Thirty minutes before admission she experienced sudden onset of cold sweats, occipital headache, dizziness and palpitation. On presentation, her blood pressure was 191/101mmHg, heart rate 71bpm. Patient was transferred to Emergency Department where cardiac events were excluded. Plasma metanephrines levels were significantly elevated, with Plasma Normetadrenaline at 16720pmol/l (reference range 0 -1180pmol/l) and Plasma Metadrenaline 11110pmol/l (reference range 0-510pmol/l). An MIBG scan confirmed suspicion of pheochromocytoma. The patient was counselled extensively on the necessity of preoperative alpha- and beta-adrenergic blockade in the context of suspected/confirmed catecholamine-secreting tumour(pheochromocytoma).

Conclusion: Pheochromocytoma crisis is a rare, life-threatening emergency. The administration of corticosteroids such as dexamethasone may trigger a catecholaminergic crisis and is contraindicated in patients with a presence of a conclusive diagnosis. While there are a few case reports of such crises triggered by the Low Dose Dexamethasone Suppression Test (LDDST) and High Dose Dexamethasone Suppression Test (HDDST), no cases have been reported following ODST. In such cases, alternative diagnostic modalities like 24-hour urinary free cortisol or late-night salivary cortisol test.