Endocrine Abstracts

Case: A 35 year old lady was found to be hypertensive following a blood pressure check in view of her oral contraceptive pill use. Because of her young age she was referred to the Hypertension Clinic. She underwent a renal ultrasound as part of the screening for end organ damage in view of her drug-resistant hypertension. The ultrasound- and subsequent CT imaging- revealed a 2.8 cm left adrenal mass measuring 44 Hounsfield Units. She denied any palpitations or headaches but did report to suffer from intermittent sweats and flushes, almost on a daily base. In addition she described an occasional sense of impending doom. Three 24 h urine collections for metadrenalines showed consistently raised normetadrenaline levels. MIBG scan showed that the mass was MIBG avid. Her blood pressure normalized on Phenoxybenzamine and she underwent an uncomplicated laparascopic left adrenalectomy. The histology of the tumour was in keeping with a pheochromocytoma. Post-surgery her bloodpressure has remained normal without medication and she is no longer experiencing symptoms of flushing. Repeat 24 h urine collections for metadrenalines have been negative. Genetic screening, requested prior to surgery, revealed that she carries a mutation in the Von Hippel-Lindau (VHL) gene. Up until now, she has not been diagnosed with other manifestations of VHL; Ophtalmology review was negative for retinal haemangioblastoma and MRI investigations were negative for cerebellar- and myelum haemangioblastoma, endolymphatic sac tumours, renal cell carcinoma, pancreatic cysts and pancreatic neuro-endocrine tumours. Her family is currently undergoing genetic screening.

Discussion: i) The clinical diagnosis of pheochromocytoma can be difficult. In our case hypertension in a relatively young person led to renal imaging, which prompted the analysis of an adrenal mass. ii) Approximately 30% of patients diagnosed with a pheochromocytoma are found to have an underlying genetic disorder, such as VHL, MEN2 and neurofibromatosis type 1. Early diagnosis of inheritable tumour syndromes and surveillance for additional tumour manifestations are key, both in the presenting patient and their extended family. iii) VHL patients might benefit from a combined Endocrinology-Genetics MDT for their lifelong follow-up.