Endocrine Abstracts

Introduction: Cystic adrenal incidentalomas are relatively rare. Large cystic pheochromocytomas are extremely rare and there are few reports of them being clinically silent.

Case presentation: We report the case of a 57-years-old man, who was admitted to our clinic for evaluation of a large cystic lesion that was found ultrasonographicaly in a typical check-up. We ordered a CT that revealed a giant right adrenal cyst (91.3×96.8×92.1 mm) with thick wall (2–5.5 mm) and no enhancement after i.v. contrast agent infusion. Before admitting the patient for surgery he was evaluated for pheochromocytoma even if he was totally asymptomatic and his blood pressure was normal in multiple measurements. The results from two 24 h urine collection specimens were a surprise: metanephrine 1800–1132 μg/24 h (normal range 20–350), epinephrine 168–130 μg/24 h (<20), norepinephrine 163–239 μg/24 h (<110), normetanephrine 1697–2171 μg/24 h (30–600), dopamine 351 μg/24 h (<600). Evaluation for multiple endocrine neoplasia type 2 syndrome was negative. The patient was preoperatively prepared with very low dose of phenoxybenzamine and propranolol. Right adrenalectomy was performed and intra- and postoperative course was uncomplicated. The surgical specimen revealed pure cystic pheochromocytoma.

Conclusion: Large cystic pheochromocytomas are very rare and often asymptomatic. Pheochromocytoma should always be ruled out in patients presenting with cystic adrenal incidentalomas, even in the absence of hypertension or other symptoms.

Declaration of interest: The authors declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project.

Funding: This research did not receive any specific grant from any funding agency in the public, commercial or not-for-profit sector.