Double Trouble: A Challenging Case of Synchronous Catecholamine-Secreting Neck Paraganglioma and Pheochromocytoma

Abstract

Background: Sympathetic paragangliomas (PGL) are regarded as catecholamine-secreting, extra-adrenal counterparts of pheochromocytomas (PCC). Hormone producing head and neck PGL (HNPGL) are exceedingly rare, as most HNPGL are biochemically silent parasympathetic tumors. Here, we present a case of synchronous sympathetic cervical PGL and PCC. Clinical Case: A 47-year-old male was referred to the Neuroendocrine Tumor Unit clinic after a failed attempt at PGL removal at another center. The patient had a 10-year history of hypertension and a family history of his mother’s sudden death. Prior to referral, he presented with a palpable 6 cm right neck mass - an uneventful core-needle biopsy pathology revealed PGL. Subsequent workup showed profoundly elevated plasma metanephrine (MN) 3000 pg/ml [<65] and normetanephrine (NMN) 3500 pg/ml [<196]. Following a week of 2 mg/d doxazosin therapy, an attempt to operate on the patient for PGL was aborted after the skin incision over the mass due to an intraoperative hypertensive crisis. Upon arrival to our unit, reassessment disclosed a sustained stage 3 hypertension that required a four antihypertensive drug regimen with doxazosin dose titration up to 16 mg/d. MRI showed a 6 cm well-defined mass that displaced the common carotid artery and internal jugular vein (IJV) anteromedially, consistent with a PGL of sympathetic chain origin. MRA identified no tumor feeding vessels that could be suitable for embolization. Ga68 DOTATATE PET/CT showed a single focus of radiotracer uptake in the right neck PGL; however, the CT did image a 1.3 cm right adrenal mass with radiographic features suggestive of PCC. The patient underwent surgery for the PGL, using vigilant intraoperative hemodynamic and upper cranial nerve monitoring. An extreme hypertensive episode (systolic BP 340 mmHg) early on during the tumor’s dissection was resolved once the venous connection between the PGL and the IJV was divided. Pathology revealed a 6 cm PGL with free surgical margins. Postoperatively, hormone levels dropped significantly (MN 98 pg/ml [<65]; NMT 198 pg/ml [<196]). Subsequently, right adrenalectomy was performed, confirming the diagnosis of a 1.6 cm PCC. At the last follow-up, the patient’s hypertension was controlled on 5 mg/d amlodipine. Plasma MN and NMN levels were normal. Genetic analysis for PGL/PCC-associated genes revealed no germline mutation. Conclusion: This case highlights the importance of preoperative workup and perioperative management of large PGL. Head and neck PGL resection may be challenging depending on tumor size and location. Early division of the venous outflow from the PGL into the IJV plays a crucial role in intraoperative hemodynamic control. A multidisciplinary team at experienced centers must be involved in every aspect of the patient’s care to achieve optimal results.