Mediastinal paragangliomas related to gene mutations.

Introduction: Paragangliomas (PGLs) related to hereditary syndromes are rare mediastinal tumors. Paragangliomas are caused by mutations in genes encoding subunits of succinate dehydrogenase enzyme (SDH).

Aim: To evaluate clinical, anatomical and functional characteristics of mediastinal paragangliomas related to gene mutations.

Material And Methods: Retrospective analysis of 75 patients with confirmed gene mutations (24 patients with , 5 , 46 with mutations) was performed. Patients underwent evaluation using computed tomography (CT), somatostatin receptor scintigraphy (SRS) (Tc-[HYNIC,Tyr3]-octreotide), I mIBG scintigraphy and urinary excretion of total methoxycatecholamines.

Results: Out of 75 patients, 16 (21%) patients (1 , 15 mutations) had 17 PGLs localized in the mediastinum. Fourteen PGLs were localized in the middle mediastinum (intrapericardial) and 3 PGLs in the posterior mediastinum. The median diameter of paragangliomas measured on the axial slice was 24.3 mm (interquartile range (IQR): 14.7-36.6), and the median volume was 2.78 ml (IQR: 0.87-16.16). Twelve out of 16 patients (75%) underwent SRS, and 11 of them (92.3%) had pathological uptake of the radiotracer. Eleven (68.75%) out of 16 patients underwent 123 I mIBG, with only 3 positive results. Symptoms of catecholamine excretion were observed in 3 patients with PGLs localized in the posterior mediastinum. All PGLs were benign except in 1 patient with the mutation and PGL detected in the posterior mediastinum, who had a metastatic disease.

Conclusions: Most mediastinal paragangliomas were related to gene mutations. They were asymptomatic, localized in the medial mediastinum, intrapericardially.