Paraganglioma

Abstract

Introduction: Paragangliomas are rare neuroendocrine tumors arising from extra-adrenal medullary neural crest derivatives. The terms pheochromocytoma and paraganglioma are often used interchangeably because morphologically and functionally these entities are almost the same. However, paragangliomas that arise in the adrenal medulla are called pheochromocytomas and those outside the adrenal gland are called paragangliomas. Paragangliomas are often discovered incidentally during imaging studies performed for other reasons. We report a case of a patient who had incidental finding of retroperitoneal paraganglioma on imaging done for evaluation of thigh and gluteal cellulitis. Clinical Case: A 24-year-old female presented with chief complaints of episodic headaches, multiple skin abscesses, fever and malaise. She has a history of Type 1DM and had been non-compliant on insulin. Vitals on presentation was significant for tachycardia with heart rate of 124, blood pressure of 119/81, respiratory rate of 16. Initial labs were consistent with DKA. CT abdomen and pelvis done for further evaluation of gluteal and thigh abscess showed incidental finding of a 3.4 cm retroperitoneal/para-aortic well-circumscribed rim-enhancing mass with central hypoenhancing component, suspicious for neoplasm such as paraganglioma. Biochemical testing was performed. 24-hour urine catecholamine levels obtained showed elevated urine norepinephrine level of 1008μg/day (reference range 15-100μg/day), urine dopamine 410μg/day (reference range 65- 400μg/day), urine epinephrine less than 2μg/day (reference range 0-20μg/day). Total urine catecholamines was elevated 1008μg/day (reference range 15-100μg/day). These results confirmed diagnosis of paraganglioma. Treatment options were discussed with the patient including surgery for removal of paraganglioma which she has currently declined. Conclusion: Diagnosis of a paraganglioma can usually be made using biochemical and radiographic testing. All patients with paraganglioma should be tested for hypersecretion of catecholamines in a 24-hour urine or serum collection, even if they do not present with a clinical picture of catecholamine hypersecretion. Importantly these extra-adrenal tumors do not have the enzymatic capacity to form epinephrine from norepinephrine as was exemplified by our case. For catecholamine-secreting tumors, biochemical diagnosis should be followed by radiological evaluation (typically either CT or MRI of the abdomen and pelvis) to locate the tumor. Treatment options are dependent on location of tumor, size, presence of symptoms and if there is metastatic disease present.