SDHD and hereditary pheochromocytoma-paraganglioma: In 6 of them, we revealed the existence of pathogenic/likely pathogenic variants of genes encoding for components of the SDH complex (SDHB, SDHD, SDHAF3, and SDHAF4), confirming their high mutation frequency not only in paragangliomas and pheochromocytomas but also in VPGLs as distinct tumor types.