Neurofibromatosis Type 1 Presenting With Adrenal Pheochromocytoma

Abstract

Abstract Background: Pheochromocytomas & Paragangliomas (PCC/PGL) are amongst the rare endocrine tumours, occurring with an incidence of 0.8 per 100,0001. Though most of them have a benign nature, they are usually hormonally active causing significant cardiovascular morbidity due to the catecholamine secretion. Approximately a third of PCC/PGL have underlying germline mutations including Neurofibromatosis type 1 (NF1). Clinical Case: A 49 year old man was reviewed for symptoms of palpitation, headache, sweating, and blurred vision. physical examination revealed signs of NF1. He had multiple neurofibromas over the skin of the back, chest and neck, café-au-lait spots on the trunk and limbs. Ophthalmology assessment revealed multiple Lisch nodules bilaterally. Urinary catecholamines were significantly elevated. His initial systolic blood pressure was 190/148 mmHg. The patient’s medical history included hypertension that used to be well-controlled with Amlodipine 10 mg and Bisoprolol 5mg. however his blood pressure was harder to control during the past year. Laboratory investigations testing included measurements of urinary fractionated metanephrines which revealed high normetanephrines with a value of 690 nmol/d (N < 240). metanephrines (485 nmol/d: N < 275) and norepinephrines (456 nmol/d: N < 440). Plasma free normetanephrines were 3.20 nmol/L (N <1.20) and free metanephrines 0.4 nmol/L (N < 0.48). CT scan of the abdomen showed a 1.3 x 2.4x 3.9 mass in the left suprarenal gland which showed showed moderate uptake on A meta-iodobenzylguanidine (MIBG) scan. And no evidence of metastases. The patient underwent laparoscopic adrenalectomy of the left suprarenal gland and histopathological examination was confirmatory of pheochromocytoma postoperatively. Conclusion:This is a case demonstrating the association between the germline mutation causing neurofibromatosis type 1 with the rare catecholamine secreting tumour (pheochromocytoma). Reference:1. Lefebvre M, Foulkes WD. Pheochromocytoma and paraganglioma syndromes: genetics and management update. Curr Oncol. 2014;21(1):e8-e17. doi: 10.3747/co.21.1579. [PMC free article] [PubMed] [CrossRef] [Google Scholar]