ODP023 Adrenal medullary hyperplasia as a differential diagnosis of paroxysmal hypertension: case report

BACKGROUND: Sporadic Adrenal Medullary hyperplasia (AMH) has been little described in the literature, being most often diagnosed during a genetic syndrome screening or the evaluation of an adrenal incidentaloma. CASE REPORT: A 51-year-old female patient presented with progressive attacks of tachycardia, headache, nausea and mild paroxysmal hypertension, which started in December 2020. She had a history of smoking and she also presented Takotsubo syndrome in 2018. She denied other comorbidities. In March 2021, she was submitted to laboratorial testing which demonstrated indeterminate plasma fractionated metanephrines by HPLC/MS: metanephrines 0.3 nmol/L (n< 0.5) and normetanephrines 1.2 nmol/L (n< 0.9) and normal serum chromogranin A level: 82 ng/mL (n<93) by Directed Proteomic. Urinary metanephrines were collected in a spot sample after an adrenergic crisis episode, confirming the biochemical diagnosis: metanephrines 255 mcg/g creatinine (n 30-165), normetanephrine 824 mcg/g creatinine (n 105-375), total 1119 mcg/g creatinine (n 150- 510) by HPLC. She was submitted to an abdominal MRI, which showed bilateral adrenal thickening with medullary predominance with hyperintense sign on T2-weighted images. It was also performed a mIBG I 131 spect and a PET-CT DOTATATO-Galium 68 without abnormal uptakes. A genetic panel by NextGeneration Sequence (NGS) was also carried out for pheochromocytoma/paraganglioma (PHEO/PGL) without pathological findings. The patient underwent laparoscopic left adrenalectomy after the use of alpha and beta blockade for one month, with pathological findings suggestive of adrenal medullary hyperplasia. However, she remained symptomatic after surgery. Once again, new urinary metanephrines in a spot sample were collected after an adrenergic crisis: metanephrines 188 mcg/g creatinine (n 30-165), normetanephrines 1229 mcg/g creatinine (n 105-375), total 1417 mcg/g creatinine (n 150-510) by HPLC, which demonstrated remaining cathecolamine excess. She underwent a contralateral laparoscopic adrenalectomy without surgical complications. An anatomopathological analysis was performed in both adrenals, which confirmed bilateral adrenal medullary hyperplasia without associated PHEO. The patient showed improvement in adrenergic symptoms and normalization of plasma fractionated metanephrines levels postoperatively, currently using hydrocortisone and fludrocortisone for the treatment of adrenal insufficiency. CONCLUSION: Adrenal Medullary hyperplasia is a rare condition, which usually presents in a milder form and is often associated with pheochromocytoma or genetic syndromes. However it should be considered in symptomatic patients without a personal or family history of PHEO/PGL, allowing an early diagnosis and treatment. Presentation: No date and time listed