Pheochromocytoma and paraganglioma in patients with neurofibromatosis type 1

Objective Individuals with neurofibromatosis type 1 (NF1) are at an increased risk of developing a pheochromocytoma or paraganglioma (PHEO/PGL). However, the best case detection strategy is unknown. Our objectives were to describe the prevalence, clinical presentation and outcomes of PHEO/PGL associated with NF1 and formulate case detection testing recommendations for PHEO/PGL. Design A retrospective cohort study from 1959 to 2015, Tertiary medical centre. Patients and Measurements We studied 41 patients with NF1 and PHEO/PGL who were identified using the PHEO/PGL and NF1 databases: 3289 and 1415 patients, respectively. Our main outcome measures were prevalence of PHEO/PGL in NF1 and occurrence of bilateral, recurrent, or metastatic disease and method of PHEO/PGL detection (symptoms vs incidental vs biochemical case detection testing). Results The prevalence of PHEO/PGL in patients with NF1 was 2.9%. The 41 patients included 23 men (56%) and 18 women. The median age at diagnosis was 41.0 years (range 14-67). The median tumour size was 3.4 cm (range 0.8-9.5). Bilateral PHEO was identified in 17% (n = 7) of patients, all women. Metastatic or recurrent disease occurred in 7.3% (n = 3). In the last 25 years, PHEO/PGL was diagnosed after incidental finding on computed imaging in 31% of patients (n = 11). Only three patients (7.3%) had PHEO/PGL discovered because of biochemical case detection testing. Conclusion We recommend patients with NF1 have biochemical case detection testing for PHEO/PGL every 3 years starting at age 10 to 14 years. Biochemical case detection testing should also be carried out prior to elective surgical procedures and conception.