Cushing's disease is rare in children and its ocurrence in identical twins is extremely rare. This paper reports on identical twins discordant for Cushing's disease. One of them first presented with a cushingoid phenotype by the age of 10. Her evaluation showed an increased urinary free-cortisol and serum ACTH. Her pattern in the dexametazone supression tests was compatible with Cushing's disease. MRI disclosed a pituitary macroadenoma which was removed by the transesphenoidal approach. Immunohistochemical studies of the tumor showed the presence of ACTH-producing cells. The patient went into clinical and laboratorial remission after surgery. She re-started to grow after the disappearance of the Cushing's phenotype but she is still shorter than her healthy sister. The latter remains disease-free 4 years after her sister's diagnosis. This represents the third such case reported in the literature. Our findings suggest that acquired factors may be responsible for the genesis of Cushing's disease.
Cushing's disease; pituitary adenoma; twins
