ACTH-INDEPENDENT UNILATERAL MULTINODULAR ADRENOCORTICAL HYPERPLASIA (UMAH) IN INFANCY: A DISTINCT ENTITY?

ACTH-independent Cushing's syndrome is either due to an adrenal tumor or to bilateral primary pigmented nodular adrenocortical dysplasia (PPNAD). The first category requires unilateral, and the latter bilateral adrenalectomy. We are reporting a 5 m old girl with ACTH-independent UMAH, clinically and historically distinct from PPNAD. who was cured by unilateral adrenalectomy. Our patient developed obesity, a moon face, and growth arrest within the first 2 m of life. There were no other features suggestive of the “Carney complex”. At 4 m of age, serum cortisol at 8, 12, 21, and 24 h was 76.8, 73.1, 115, and 84.4 μg/dl. non-suppressible by dexamethasone (2 and 8 mg/1.7 m2). and ACTH was undetectable (before and after CRF). Ultrasound and NMR showed a multinodular enlarged right and a normal left adrenal A right-sided adrenalectomy and a biopsy of the left adrenal revealed both diffuse and nodular cortical hyperplasia without internodular atrophy and with preservation of the fetal cortex in the right adrenal, and normal macro- and microscopic morphology in the contralateral gland, both features being clearly distinct from classical PPNAD. Surgery resulted in clinical and biochemical cure, and 5 m later, the hypothalamo-pituitary-adrenal axis was still partially suppressed, necessitating low-dose hydrocortisone replacement. On the basis of the unilateral process documented both morphologically and biochemically, and the specific histology of the diseased adrenal, we suggest that 1) UMAH in infancy is a separate entity distinct from PPNAD, and 2) the treatment of choice consists of unilateral adrenalectomy.