FRI245 Non-classic CAH Presenting As Bilateral Adrenal Incidentalomas

Abstract

Abstract Disclosure: Y.A. Chin: None. T. Puar: None. T. King: None. Introduction: Congenital adrenal hyperplasia (CAH) due to 21-hydroxylase deficiency is an autosomal recessive disorder. Non-classic CAH usually presents in late childhood or asymptomatic may remain undiagnosed. Adrenal incidentalomas have been reported as a presentation of CAH. Clinical Case: A 56-year-old man presented with a 4-day history of epigastric pain associated with chest discomfort and diaphoresis. There was no postural giddiness, vomiting, paroxysm or constitutional symptoms. He was a smoker, his parents were non-consanguineous and he had fathered 2 children. He was tachycardic at 114 bpm, but normotensive (129/89 mmHg) with no postural hypotension and no abnormal pigmentation. He had evidence of heart failure with bibasal crepitations and pedal oedema. Secondary sexual characteristics were normal and testicular volume was 15 mls bilaterally with no palpable mass. CT abdomen showed grossly enlarged bilateral adrenal glands with heterogenous nodular appearance with several focal hypodense cystic components, with absolute washout <60%. Biochemistry was consistent with primary adrenal insufficiency (PAI); 8am serum cortisol 188 nmol/L, with peak cortisol post 250mcg synacthen of 195 nmol/L. Serum ACTH was elevated at 254.6 ng/L, aldosterone and renin were normal and 24hr urinary normetanephrine was mildly elevated at 1982 nmol/d (NR 600-1900 nmol/d). Echocardiography revealed severe global hypokinesia (EF 20%) but myocardial perfusion imaging was negative for ischemia. In view of suspicion for tuberculosis, malignancy or infiltrative disease, CT guided adrenal biopsy was performed. Histology showed hyperplastic adrenal cortex with lipofuscin pigments, focal lymphohistiocytic infiltrates. No lymphoplasmacytic infiltrate with IgG 4 plasma cells, granuloma, malignant cells or amyloid deposits were seen. Serum 17-OHP level later came back elevated at 39.7 nmol/L (NR 1.8-10.4 nmol/L). DNA sequencing of CYP21 revealed compound heterozygous mutations in c.292+1G>A and c.518T>A, both of which have been reported to be causative of CAH. He was transitioned from stress dose to physiological glucocorticoid replacement and ACTH normalised on subsequent outpatient visits. Follow up imaging after 6 months and 2 1/2 years revealed no change in size or morphology of the adrenal glands. Follow up echocardiography showed no improvement in ejection fraction despite intensive heart failure treatment. Conclusion: Nodular adrenal hyperplasia is well described among CAH individuals, especially in those with inadequate glucocorticoid replacement and chronically elevated ACTH levels. There was no change in size of the adrenal lesions despite adequate glucocorticoid replacement. Improvement of cardiac function with glucocorticoid replacement has been reported in paediatric patients with CAH, but our case did not show any improvement on serial echocardiography. Presentation: Friday, June 16, 2023