Endocrine Abstracts

Pheochromocytomas are rare tumors located in the adrenal medulla, that derive from the chromaffin cells and produce catecholamines. They are an uncommon cause of hypertension, and only 50% of the patients present symptoms compatible with this pathology. Here we describe the case of a 67-year-old man who was referred with h/o mild headache, hypertension and adrenal incidentaloma detected by CT abdomen and pelvis which showed 4.5 cm indeterminate nodule in the left adrenal gland. PMH includes T2DM, prostate cancer treated with radical prostatectomy and salvage radiotherapy. His BP was 177/100 mmhg in the clinic and other systemic examinations were unremarkable, no palpable mass was found in neck or abdomen. There was no family history of any adrenal, thyroid, parathyroid or pituitary gland problem. Subsequently, MRI scan of adrenal gland showed 5.5 cm indeterminate nodule in left adrenal gland though in-phase/out-phase sequence couldn’t be done. Laboratory studies revealed an elevated plasma non metanephrine of 10,506 pmol/l (normal limit up to 1180), plasma metanephrine level was 272 pmol/l (normal limit up to 272), plasma 3-methoxytyramine was 211 pmol/l (normal limit up to 180). Other blood tests including overnight dexamethasone suppression test, plasma aldosterone and renin ratio, serum calcium, TSH, urea and electrolytes, PSA were in acceptable normal limit. A diagnosis of pheochromocytoma was made and the patient was started on phenoxybenzamine to control his blood pressure with the aim of adding betablocker subsequently. The case has been discussed in adrenal MDT and decided for left sided adrenalectomy after discussion with the patient. He is currently waiting for the left adrenalectomy. This case highlights the importance of having a high index of suspicion to diagnose this rare tumor presented with very subtle clinical findings and adrenal incidentaloma on imaging. Early diagnosis and subsequent interventions with surgery and antihypertensive medications can reduce morbidity and mortality.