Endocrine Abstracts

Introduction: Phaeochromocytoma (PHAEO) and paraganglioma (PGL) are neuroendocrine tumors arising from neural crest-derived cells either in the adrenal gland (PHAEO) or along the central sympathetic and parasympathetic chains (PGL), including the carotid body. There is convincing evidence linking hypoxia pathways with development of PHAEO/PGL especially with genetic susceptibility. Association between PHAEO and PGL and cyanotic congenital heart disease (CHD) are well recognised owing to chronic hypoxia in oxygen sensitive tissues such as carotid body and chromaffin cells.

Case: We present a case of 30 year old lady with cyanotic congenital heart disease with tricuspid atresia and univentricular physiology who had palliative Fontan and Glen procedure at the age of 4 years. Prior to her recent presentation with pulmonary haemorrhage, she had 10 months history of headaches and 4 months history of worsening palpitation on the background of atrial fibrillation for which she was started on beta blockers. Within couple of months, she represented again with ischemic left middle cerebral artery infarct which was treated with thrombectmy and made a full recovery. During the investigations a 5×4.9 cms retroperitoneal and bilateral carotid body lesions were identified raising the suspicion for paragangliomas. PGL were confirmed biochemically with raised catecholamines (24-h urine Urinary normetadrenaline – 21.90 umol/24 h and plasma normetadrenaline level – >32 000 pmol/l) and with metaiodobenzylguanidine (MIBG) scan. She was started on alpha blockers with the good symptoms response and has been referred for genetic evaluation. Her paragangliomas are currently being managed conservatively given the complex cardiac condition (Failing Fontan) as guided by the multidisciplinary team.

Conclusion: Patients with CHD are at increased risk for developing PHAEO-PGL. There is a considerable overlap of symptoms between their complex cardiac condition and with those due to catecholamine secretion. Cardiovascular complications associated with untreated PHAEO-PGL could further complicate the already compromised cardiac status. The rarity and unfamiliarity often poses challenge in the early diagnosis and management and hence a high level of suspicion and vigilance is required to diagnose this condition. Robust MDT with representation from multiple specialties is one of the key essentials in managing such complex neuroendocrine condition.