[Isolated ACTH deficiency]

The isolated ACTH deficiency is a scarcely diagnosed disease of heterogeneous nature. Two patients with isolated deficiency of ACTH in whom the initial diagnosis was of primary suprarrenal failure are reported. In the first case this diagnosis was performed after hospital admission for deterioration of the level of consciousness and the development of an acute suprarrenal crisis in the course of nosocomial pneumonia. In the second case the clinical manifestations began as weakness, anorexia, weight loss and lymphocytosis with eosinophilia. In both patients an increase in the thyrotropic hormone was detected leading to suspicion of the existence of associated primary hypothyroidism. Finally, several studies were carried out (basal measurements of cortisol and ACTH, stimulation with continual perfusion of ACTH, insulinic hypoglycemia, global study of adenohypophysary function, ACTH CRF release factor test, computerized tomography of the pituitary region) in both patients leading to the definitive diagnosis of isolated ACTH deficiency of idiopathic cause of possible pituitary origin without the existence of other associated hormonal deficiencies.