Solitary Langerhans-cell histiocytosis of the clivus and sphenoid sinus with parasellar and petrous extensions: case report and a review of literature.

Background: In Langerhans-cell histiocytosis, there occurs an uncontrolled clonal proliferation of dendritic cells that have Langerhans cell like characteristics. In this report, a unique case of a solitary, skull base Langerhans-cell histiocytosis (LCH) is described.

Case Description: A 15-year-old boy presented with raised intracranial pressure, decreased visual acuity, bilateral abducent nerve palsy, and 25% hypoesthesia in all three divisions of the right trigeminal nerve.

Association between an aplastic basilar artery, unaccompanied by a primitive carotid-vertebrobasilar anastomosis, and multiple aneurysms on the dominant posterior communicating artery.

Basilar artery (BA) aplasia when unaccompanied by a primitive carotid-vertebrobasilar anastomosis is exceedingly rare. The association of BA aplasia with two aneurysms on the dominant posterior communicating artery (PCoA) has not been previously reported. This 40-year-old man presented in a state of drowsiness and responded to simple commands only after being coaxed.