A middle aged woman with isolated ACTH deficiency associated with transient growth hormone deficiency

Isolated ACTH deficiency (IAD) is a rare entity characterized by secondary adrenal insufficiency with low levels of serum cortisol, decreased production of ACTH, adequate secretion of other pituitary hormones and normal pituitary structure on radioimaging. The prevalence of IAD as a cause of secondary adrenal insufficiency has not been determined. Impairment of growth hormone (GH) secretion has been noted in 20 to 30% of patients with IAD which is normalized after glucocorticoid replacement. We report the case of a 50 years-old female with symptoms and laboratory results suggestive of adrenal insufficiency. Insulin tolerance test confirmed ACTH and growth hormone deficiency. The rest of the anterior pituitary hormones were normal. A pituitary MRI was unremarkable. Glucocorticoid replacement therapy started and eight months afterwards glucagon stimulation test revealed persistent ACTH deficiency but nor- mal growth hormone secretion. IAD can present with nonspecific symptoms and could be potentially fatal in an acute stressful period. Prompt recognition is essential to decrease morbidity and mortality.