Endocrine Abstracts

Here we present two interesting cases of pheochromocytoma with unusual presentation.

Case1: A 61-year-old gentleman presented with syncope after noticing small amount of haematuria. His initial working diagnosis was vasovagal syncope but on further exploration, he reported previous history of palpitations and atypical chest pain. He was non-smoker with longstanding hypertension. His CT(urogram) showed incidental left adrenal nodule after undergoing workup for haematuria. Urine metanephrines were elevated 4-times above upper limit of normal range with normal overnight dexamethasone suppression test (DST) excluding any iatrogenic cortisol excess. His MRI(adrenals) and MIBG scan confirmed 3.2cm left-sided phaeochromocytoma. His elective left adrenalectomy was performed uneventfully. Histology showed a composite phaeochromocytoma, PASS 3, with ganglioneuromatous elements, present at margin. At 3-month follow-up, he remained normotensive and repeat plasma metanephrines were normal. He was planned for repeat CT and genetic testing.

Case2: A 36-year-old gentleman was referred to endocrinology for incidental 3.5cm indeterminate adrenal nodule on CT (abdomen) after investigating abdominal symptoms. He denied constitutional symptoms, chest pains, palpitations, syncope, excessive weight gain, sweating or flushing. His initial CT and MRI (adrenals) could not differentiate between lipid-poor adrenal adenoma, phaeochromocytoma, adrenocortical carcinoma or adrenal metastasis. Given his age and tumour size, surgical intervention was suggested. However, as he was not keen on surgery initially, serial imagings were planned. On follow-ups, he started experiencing flushing and headaches. His blood/24-h-urine normetadrenaline were elevated with normal overnight DST. His serial MRIs later demonstrated avidly-enhancing 34-mm left-sided adrenal nodule and MIBG found avidly intense uptake, consistent with pheochromocytoma. Given the above findings, patient agreed to proceed with adrenalectomy.

Conclusion: Our 2 cases of pheochromocytoma highlight the importance to exercise high degree of suspicion in sporadic pheochromocytoma which can present with atypical features at diagnosis and during follow-up.