Pheochromocytomas and paragangliomas in patients with congenital heart defects

The correlation between pheochromocytoma/paraganglioma (PHEO/PGL) and cyanotic congenital heart defects is rare but not coincidental. Research suggests that the development of PHEO/PGL in these patients maybe explained by chronic hypoxia, disruptions in the sympathetic nervous system, and potential genetic predisposition. These factors may provoke the tumor transformation of chromaffin cells. Additionally, diagnosing PHEO/PGL in patients with heart defects is complicated by hemodynamic disturbances that mask the characteristic sympathoadrenal crises of PHEO/PGL. The occurrence of these neoplasms can exacerbate the clinical course of congenital defects due to increased catecholamine secretion, leading to vasoconstriction and worsening hypoxia. We present two clinical cases of PHEO/PGL in the context of congenital heart defects, with patients observed and treated at the N.N. Blokhin National Medical Research Center of Oncology and the A.N. Bakoulev National Medical Research Center of Cardiovascular Surgery. These observations emphasize the importance of vigilance for symptoms of tachycardia and uncontrolled hypertension in such patients. Despite their rarity, the relationship between these pathologies must be considered for accurate diagnosis and optimal treatment selection.