Symptomatic Rathke's cleft cyst simulating arachnoid cyst--case report.

A case of symptomatic Rathke's cleft cyst simulating an arachnoid cyst is presented. Although computed tomography and magnetic resonance imaging showed that the cyst content was identical to cerebrospinal fluid, there was faint contrast enhancement in part of the wall. Histological observation suggested that the somewhat vascular connective tissue associated with nests of pituitary cells might have contributed to the enhancement. This type of Rathke's cleft cyst requires further clinical and neuroradiological studies.