ODP042 Hereditary Pheochromocytoma with a Novel Mutation in the Succinate Dehydrogenase Subunit A gene

Abstract

Abstract Pheochromocytomas and paragangliomas (PPGLs) are rare neuroendocrine tumorswith a diverse clinical presentation. Pathogenic variants in the genes encoding different subunits of the succinate dehydrogenaseenzyme complex that plays a central role in energy metabolism,have been linked to hereditary PPGL syndromes. Here wereport 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. She denied any symptoms of catecholamine excess but her plasma metanephrines level was elevated. Family history was significant for breast cancer in her motherand sister. Computed tomography (CT) scan of the abdomen showed bilateralbulky adrenal glands with a lesion in theleft adrenal gland. Magnetic resonance imaging (MRI) abdomen was performed for further characterization, the lesion measured approximately 2.8×2.6 cm with imaging characteristics suggestive of pheochromocytoma. Iodine-131 Metaiodobenzylguanidine (MIBG) whole body scan showed abnormal focal radiotracer uptake at the left adrenal gland, and she then underwentleft sided robotic adrenalectomy. Following surgery, the patient had symptomatic relief. Histopathology confirmed the diagnosis of pheochromocytoma measuring 2×2×1.5 cm with PASS (Pheochromocytoma of the Adrenal gland Scaled Score) score of 1/10, due to cellular monotony. Genetic testing revealed that she was positive for a pathogenic mutation in the SDHA gene consistent with the diagnosis of hereditary PPGL syndrome. Genetic testing was performed for the patient due to her presentation with bilateral adrenal masses and family history of cancers. Guidelines recommend genetic testing for patients with features that indicate a high likelihood of a hereditary cause for PPGL, including positive family history, syndromic features, and multifocal, bilateral, or metastatic disease. SDHA mutated PPGLs have diverse phenotypes and may be at high risk of metastasis. They are also associated with extra-adrenal tumors, include gastrointestinal stromal tumours (GIST), pituitary adenomas, papillary thyroid carcinoma, renal carcinoma and breast carcinoma. The detection of susceptibility genes for hereditary PPGL syndromes has key implications, for surveillance to detectextra-adrenal disease and recurrent tumors, as well as for consideration of genetic testing forfamily members. Presentation: No date and time listed