A Case Of Cystic Pheochromocytoma With Hypertension And Headaches Mimicking A Large Pancreatic Cystic Tumor

ABSTRACT Objective: Cystic pheochromocytomas can become enlarged without abdominal symptoms and can potentially be confused with other abdominal cystic tumors. Methods: We report here a case of a 45-mm cystic pheochromocytoma that was initially considered a pancreatic cystic tumor. The patient had a 4-year history of treatment for hypertension and occasional headaches. Left cystic pheochromocytoma was diagnosed based on excessive catecholamine levels, 18F-fluoro-2-deoxy-d-glucose positron emission tomography/computed tomography (18F-FDG PET/CT), and 123I-metaiodobenzylguanidine (123I-MIBG) scintigraphy. Results: Left adrenalectomy ameliorated the patient's hypertension and headache. Pathologic findings showed an enlarged cyst with an irregular, thick wall adherent to the normal adrenal tissues. Conclusion: A large cystic pheochromocytoma can be misdiagnosed as a large pancreatic cystic tumor. CT and magnetic resonance imaging (MRI) are less important in excluding the possibility of pheochromocytoma than biochemical evaluation. When adrenal glands are not identified on CT or MRI, 18F-FDG PET/CT or 123I-MIBG scintigraphy should be considered.