Endocrine Abstracts

Introduction: Von Hippel-Lindau syndrome is an autosomal dominant condition due to the germline mutation of the VHL gene. Approximately 80% of VHL cases are inherited and 20% occurred because of de novo event. Phaeochromocytomas occur in 10 – 20% of VHL families. Bilateral phaeochromocytomas are more common than extra-adrenal paraganglioma and the majority secrete normetanephrine.

Case: A 25-year-old lady of Asian origin was admitted to the hospital due to the evidence of hypertensive retinopathy and systolic blood pressure of more than 200 mmHg following attendance to the eye clinic with floaters and headache. She had five months history of headache, fatigue and palpitations prior to admission. She has medical history of iron deficiency anaemia due to menorrhagia and family history of hypertension in mother, who is in her 40s. She was screened for endocrine causes of hypertension. Her plasma normetanephrine level was elevated at >25000 pmol/l (reference range 0-730). CT (adrenals) demonstrated left adrenal lesion of 2 cm with indeterminate features and 5.5 cm right adrenal solid and cystic lesion. She was referred to the Adrenal MDT. MIBG scan showed bilateral phaeochromocytomas and an indeterminate tracer-avid retroperitoneal nodule inferior to the right adrenal mass. Her fasting gut hormone profile and bone profile were normal. Further enquiry revealed that her paternal grandmother had VHL mutation, but her father does not carry the gene. Her maternal uncle and maternal grandfather passed away from kidney failure. Her parents are second cousins. Genetic profile for familial phaeochromocytoma and paraganglioma panel R223 was carried out. Her genetic test revealed that she has VHL gene (c.250G>A heterozygote). Her mother was later tested and found to carry the same gene. She was managed pre-operatively with doxazocin and bisoprolol. She had MRI head and spine, which did not identify any paraganglioma. Ophthalmology assessment did not report any retinal angiomas. She had bilateral open adrenalectomy. Histopathology demonstrated left sided phaeochromocytoma of 2 cm (PASS score 1/20), and right sided phaeochromocytoma of 6 cm (PASS score 6/20), ectopic adrenal tissue identified to the right of inferior vena cava with Ki67 of 3.5%. Post operatively, she was managed with hydrocortisone and fludrocortisone replacement. Her plasma normetanephrine levels have normalised.

Conclusion: Genetic screening and counselling is important in VHL syndrome. The management of phaeochromocytoma requires a multidisciplinary approach. Patients should remain on close surveillance for recurrence of phaeochromocytoma and other complications of VHL.