Basilar artery duplication associated with pituitary duplication: a new finding

Abstract

Pituitary duplication is a rare malformation, reported previously in approximately 18 patients. It is usually unsuspected before imaging, although it occurs most commonly in association with complicated midline and skull base anomalies. It is easily shown by MR imaging. Five new cases of pituitary duplication were diagnosed by using MR imaging studies reviewed at the Hospital for Sick Children. Among the many associated midline abnormalities, partial basilar artery duplication is a previously undescribed finding that we observed in all our cases. Cases of basilar artery duplication or fenestration are associated with altered flow dynamics, leading to a higher incidence of aneurysms. Periodic surveillance for this potential complication may be warranted.

Fig 1.

Images from the case of a 1-year-old male patient with macrocephaly and mild facial dysmorphism (case 1). A, Sagittal view T1-weighted MR image shows tubomammillary fusion (arrow). B, Coronal view T1-weighted MR image shows the bright signal intensity in the posterior pituitary of a duplicated gland. C, Frontal projection time-of-flight MR angiogram shows the distal split of the basilar artery (arrow).

Fig 2.

Images from the case of a 2-day-old female patient who presented with a protruding whitish mass from the oral cavity (case 2). A, Sagittal view T1-weighted MR image shows tubomammillary fusion (short arrow) and the oral dermoid (long arrow). B, Coronal view T1-weighted MR image shows duplicated pituitary gland (arrows). C, Coronal view T2-weighted MR image shows two infundibular stalks (arrows). D, 3D CT scan shows duplicated sella.

Fig 3.

Images from the case of a 1-day-old female patient with craniofacial deformity (case 3). A, Coronal view T1-weighted MR image shows duplicated pituitary gland (arrows). B, Coronal view T2-weighted MR image shows duplicated basilar artery (arrows). C, Axial view T2-weighted MR image shows each superior cerebellar artery (arrows) arising separately from the duplicated basilar artery.

Fig 4.

Images from the case of a premature female patient who was born at 28 weeks (case 4). A, Coronal view T1-weighted MR image shows duplicated pituitary gland (long arrows). Short arrow indicates germinal matrix bleed on the right side. B, Time-of-flight MR angiogram shows duplicated distal basilar artery. C, Autopsy probe points to the origin of the duplicated distal basilar artery. Note the thickened hypothalamus.

Fig 5.

Images from the case of a 2-day-old female patient with suspected choanal atresia (case 5). A, Sagittal view T1-weighted image shows characteristic tubomammillary fusion (asterisk). B, Coronal view T1-weighted image shows the bright duplicated pituitary gland (arrows). C, Source MR angiograms obtained through the vertebrobasilar system. Arrowhead indicates duplicated basilar artery. Short arrows indicate superior cerebellar arteries arising from duplicated basilar artery. Long arrows indicate posterior cerebral artery. D, Oblique view MR angiogram shows the superior cerebellar arteries (SCA) originating from the distal duplicated basilar artery. PCA, posterior cerebral artery.