Endocrine Abstracts

The mutations of succinate dehydrogenase subunits (SDHA, SDHB, SDHC, SDHD) are linked with a predisposition to develop pheochromocytoma and paraganglioma, often in diferent locations of the body. With greater acces to genetic tests, current estimations suggest that 40-50% of pheocromocytoma and paraganglioma cases are inherited and half of them are due to SDH mutations. These mutations can be associated with other tumours like renal carcinomas, gastrointestinal stroma tumours and pituitary adenomas. Affectation of subunit B is described with the most probability of malignant illness in the type 4 paraganglioma syndrome. We report a case of a patient who presented with multifocal paraganglioma and prolactinoma secondary to SDHB mutation, followed in our center in Alcorcon (Madrid) in the year 2022.

Case Report: 24 year old woman with no medical background and no remarkable familiar history. Derived after finding of pituitary macroadenoma on MRI (23×14×17 mm imprinting optic chiasma) in the context of amenorrhea and elevated serum prolactine (266 ng/ml). This study also inform a incidental lesion in left yugular región inferior to craneal base, that could be a 34 mm tympanic glomus. With normal visual field testing, Cabergoline is initiated to manage hyperprolactinemia and reduce macroadenoma volume. Posterior hormone study only detected subtle elevation of noradrenaline and normetanefrine in 24 hours urianalysis. MIBI-scintigraphy was negative in the possible glomus but there was pathologic deposit in the mid abdomen which was described in a subsequent body CT as another 30 mm intrabdominal paraganglioma. Confirmed these two hypermetabolic nodules in a 18-FDG PET imaging with high expression of somatostatin receptors in a Octreoscan. We decided to first resect the abdominal nodule with previous alfa-blocking with Doxazosine, confirming histological and inmunohistochemical characteristics of sympathetic paraganglioma. The genetic study demonstrated that the patient bear the mutation c166_170CCTCA of the SDHB gene. Surgery of the yugular lesion was dismissed, opting for radiotherapy. Currect prolactine and catecholamine values are normal. Genetic screening of the patient’s family still pending.

Conclussion: Mutations causing the pheochromocytoma/paranganglioma can be linked with pituitary adenomas, specially the SDH ezymatic complex. Genetic screening should be performed in all patients with these two entities alongside with a mangement in accordance with practice guidelines.