Clinical Features of Pheochromocytoma and Paraganglioma in Patients with Neurofibromatosis Type 1

Presentation Number: SUN 398
Date of Presentation: April 2nd, 2017

Elisabeth Joye Petr* and Tobias Else
University of Michigan, Ann Arbor, MI

Abstract

Pheochromocytomas (PCC) and Paragangliomas (PGL) are rare endocrine tumors. Although most PCC/PGL are benign, they can cause cardiovascular morbidity and mortality due to excess catecholamine release. Roughly 30% of patients with PCC/PGL have germline genetic mutations that predispose them to tumor development. However, screening guidelines are only established for patients with MEN2 and VHL. Despite the fact that neurofibromatosis type 1 (NF1) is common and PCC/PGL occur in up to 7% of NF1 patients, the phenotype of PCC/PGL in NF1 is not well described, and there are no recommendations for PCC/PGL screening.

In order to characterize NF1-associated PCC/PGL, we used electronic search algorithms to identify patients with NF1 and PCC/PGL seen at a large academic referral center. We identified and reviewed the charts of 17 patients; 14 were referred with a diagnosis of PCC/PGL and 3 were diagnosed at our institution.

The average age of PCC/PGL diagnosis was 41 years (20-62 years) and both genders were equally affected (8 female/9 male). Seven PCC/PGL were incidentally found on imaging; ten were identified during workup of suspicious symptoms. Nine patients had hypertension, one patient had orthostatic hypotension. The remaining seven were normotensive, but at least five of these had tachycardia with HR>90. Most importantly, six patients had a history of cardiovascular crises including cardiac arrest, myocardial infarction, intraoperative labile blood pressures, and extreme tachycardia during spinal anesthesia. Average tumor size was 4cm (1.5-6.8cm). Two patients had bilateral PCC’s, one of whom also had a head and neck paraganglioma, and one patient had an abdominal PGL. Only one patient had possible metastatic disease at presentation and a second patient developed metastatic disease after initial surgical resection. Biochemical data was available for 16 patients and of these 15 had elevated plasma or urine catecholamine or metanephrine levels. Nine patients had MIBG scans, all of which were positive.

In summary, NF1-associated PCC/PGL presents at a similar age as sporadic cases. The majority are benign unilateral tumors, which are biochemically active and visible on MIBG scans. Almost half were discovered incidentally on imaging. The high incidence of cardiovascular crises often associated with surgical procedures found in this cohort highlights the importance of PCC/PGL screening in the NF1 population.

 

Nothing to Disclose: EJP, TE