Hereditary Pheochromocytoma With a Mutation in the Succinate Dehydrogenase Subunit A Gene

Pheochromocytomas and paragangliomas (PPGLs) are rare neuroendocrine tumors with diverse clinical presentations. Pathogenic variants in the genes encoding different subunits of the succinate dehydrogenase enzyme complex that plays a central role in energy metabolism have been linked to hereditary PPGL syndromes. Here we report a rare case of hereditary pheochromocytoma with a novel mutation in the succinate dehydrogenase subunit A (SDHA) gene. A middle-aged woman presented with left-sided abdominal pain and was incidentally found to have bilateral adrenal lesions on abdominal imaging. Imaging characteristics were suggestive of pheochromocytoma. She denied any symptoms of catecholamine excess but her plasma metanephrines level was elevated. Iodine-131 metaiodohenzylguanidine (131I-MIIIG) whole-body scan showed abnormal focal radiotracer uptake at the left adrenal gland, and she then underwent left-sided adrenalectomy. Following surgery, the patient had symptomatic relief and histopathology confirmed the diagnosis of pheochromocytoma. Genetic testing revealed that she was positive for a pathogenic mutation in the SDHA gene consistent with the diagnosis of hereditary PPGL syndrome. The detection of susceptibility genes for hereditary PPGL syndromes has key implications, for surveillance to detect extra-adrenal disease and recurrent tumors, as well as for consideration of genetic testing for family members.