Endocrine Abstracts

Aberrant adrenal LH expression is a rare cause of adrenal Cushing’s syndrome (CS) leading to transient hypercortisolism during pregnancies and ACTH-independent macronodular adrenal hyperplasia (AIMAH) after the sustained postmenopausal increase of LH secretion. Subclinical CS due to aberrant LH expression has very rarely been described. Herein, we report a case with aberrant LH/hCG adrenal receptor mediated subclinical CS in a patient with incidentally discovered AIMAH and the outcome following long-term leuprolide acetate administration.

Case report: A 54 postmenopausal female presented with bilaterally enlarged adrenals discovered incidentally following abdominal CT-scan performed for assessment of a uterine bleed. She had no hypertension, osteoporosis, diabetes, hirsutism, weight gain or other stigmata of CS. Urinary free cortisol (UFC) excretion was borderline high associated with incomplete cortisol (F) suppression on a low dose dexamethasone suppression test (LDDST). She was initially treated with hysterectomy and left adrenalectomy. Subsequent investigations in our unit revealed borderline elevated midnight plasma F and UFC excretion and, incomplete F suppression following a LDDST. Investigations for aberrant receptor expression revealed no F response following upright posture and meal tests but a marked F increase following LHRH (100 μg i.v.) and hCG (10 000 U i.m.) administration. Treatment with leuprolide acetate (3.75 mg i.m. every 4 weeks) led to a gradual reduction of UFC and midnight F and, complete F suppression after LDDST. Moreover a gradual increase of basal ACTH levels was observed. The size of the hyperplastic right adrenal remained unchanged.

Conclusions: This case illustrates the necessity to include LH aberrant receptor expression screen in asymptomatic patients with bilateral adrenal incidentalomas. Moreover, since the LH decrease induced by leuprolide acetate leads to normalisation of pituitary–adrenal function, this treatment may be recommended even in patients with subtle glucocorticoid excess.