A Case of Ectopic Rathke's Cleft Cyst in the Prepontine Cistern.

A Rathke's cleft cyst (RCC) is a benign pituitary cyst derived from the remnant of Rathke's pouch, and usually presents as an intrasellar lesion with varying degrees of suprasellar extension. However, to date, a description of a primary prepontine RCC with no intrasellar component has not been reported. The author describes an exceptional case of a symptomatic RCC located behind the sella turcica in a 41-year-old woman who presented with severe headache. The author also provides an embryological hypothesis of the development of an ectopic RCC, with a special emphasis on radiologic characteristics.