Agenesis of the internal carotid artery with a trans-sellar anastomosis: CT and MRI findings in late-onset congenital hypopituitarism

A 29-year-old woman with a history of hypothyroidism since early childhood developed hypopituitarism. CT and MRI revealed anterior pituitary hypoplasi a, an ectopic posterior lobe, a Chiari I malformation and agenesis of the r ight internal carotid artery with a transsellar anastomosis. This constella tion of findings constitutes a previously unreported association in congeni tal hypopituitarism of late onset. The usefulness of imaging modalities and the pathogenic implications are also discussed.