IMPE Abstracts

Introduction: Paragangliomas (PGLs) are uncommon neuroendocrine tumors. These tumors can originate from either the sympathetic or parasympathetic paraganglia. Cardiac PGLs (CPGLs) are extremely rare, as thoracic localization represents less than 2% of PGLs. There are few reported cases in pediatric age. The most frequent cause of inherited phaeochromocytomas/paragangliomas are germline pathogenic variants in Succinate Dehydrogenase Subunit B, C and D genes (SDHB/SDHC/SDHD).

Case report: a 12-year-old boy was referred to our hospital due to severe hypertension. He had no relevant pathological history, and a few months ago was evaluated by cardiology for an episode of headache and diaphoresis. Severe hypertension (199/130) was detected on several occasions so he started on beta-blockers, without improvement. He had a normal abdominal CT scan and elevated urinary metanephrine levels. With these results, doxazosin was indicated. At first visit he had normal height and weight, cardiac frequency and blood pressure (BP) were 88 bpm and 110/80 respectively (under doxazosin), and tanner stage was V. PET-CT was performed, which reported an intrapericardial lesion, at right atrial topography, described as a lobulated mass of 49x41x47 mm, volume 52 cc, with intense heterogeneous enhancement in the arterial phase after the administration of IV contrast. Treatment with Doxasozine was titrated until reaching adequately controlled BP. BP was monitored in the office with a complementary study of home BP monitoring weekly due to COVID 19 lockdown, with adequate control of pre-surgical BP. Tumor resection was performed, with favorable evolution and adequately controlled BP records. Actually his BP is normal, without any treatment, normal urinary metanephrine levels and normal PET CT. Pathology report confirmed diagnosis of Paraganglioma with positive immunostaining for chromogranin, synaptophysin and S100. Sequencing of SDHB and SDHD genes was done, finding 4 variants classified as benign or probably benign in SDHD.

Conclusion: We emphasize the importance of PET CT when CT is negative. A multidisciplinary approach was essential in order to achieve a timely diagnosis and a successful treatment. Because no pathological variants were found, molecular diagnosis will be extended. If a pathological variant is present, this may impact on the risk of recurrence and/or malignancy.