Introduction: Since pheochromocytomas present with various complications due to catecholamine hypersecretion, their perioperative management needs special attention. Case presentation: A 45-year-old man visited our hospital with a complaint of abdominal swelling. Radiological and endocrinological assessments determined the tumor as a giant (>20 cm) cystic pheochromocytoma. After administration of doxazosin, the patient underwent radical surgery. Since the tumor was extremely large and fixed to surrounding structures, we punctured it and aspirated cystic fluid to improve the tumor's mobility. However, during the aspiration, the patient developed acute hypotension, which could be reversed by suction withdrawal and vasopressor administration. A similar event occurred during a second aspiration. Eventually, the tumor was successfully excised with negative surgical margin. The cystic fluid proved to contain extremely high concentrations of catecholamines, which might result in the hypotension. Conclusion: We report the first case who developed acute hypotension due to aspiration of cystic fluid from giant pheochromocytoma. Keynote messagePheochromocytomas present with various complications due to catecholamine hypersecretion, and thus their perioperative management needs special attention. We report a case who developed acute hypotension due to aspiration of tumor cystic fluid during resection of giant pheochromocytoma. The cystic fluid proved to contain extremely high concentrations of catecholamines, which might result in the hypotension. The present report would promote physicians' awareness of this possible intraoperative complication and lead to safer pheochromocytoma surgery.

Pheochromocytoma/paraganglioma (PPGL)-related hypercatecholaminemic crisis is a rare lethal condition caused by uncontrolled catecholamine secretion, occasionally leading to critical fluctuation in blood pressure (BP). Emergent transcatheter arterial embolization (TAE) has been employed for spontaneous PPGL rupture, but never, to our knowledge, for critical fluctuation in BP associated with PPGL-related hypercatecholaminemic crisis. We describe here our experience utilizing this method to control critical fluctuation in BP associated with this crisis in a 44-year-old man with an unruptured retroperitoneal paraganglioma. The patient experienced sudden severe left abdominal pain and came to our emergency department, where he exhibited severe fluctuation in BP and underwent laboratory testing that showed hypercatecholaminuria and computed tomography (CT) that revealed a left retroperitoneal tumor with no apparent intra- or retroperitoneal hematoma. We performed emergent TAE from the left inferior phrenic artery using gelatin sponge, which stabilized his BP and relieved his abdominal pain. Histologic examination following elective surgical resection of the tumor confirmed our diagnosis of unruptured retroperitoneal paraganglioma. We believe that TAE represents an important option for the emergent treatment of the critical BP fluctuation associated with PPGL-related hypercatecholaminemic crisis.