Relationship Between Clinical Features and T2-Weighted Magnetic Resonance Images in Symptomatic Rathke Cleft Cysts

It is not known when surgery is appropriate for the treatment for incidental Rathke cleft cysts because knowledge of their natural history is lacking. In this study, we sought to determine whether symptomatic Rathke cleft cysts could be distinguished by their signal intensities in magnetic resonance (MR) images. We analyzed the relationship between these signal intensities and clinical manifestations of the cysts and their patterns of expansion.

MR signal intensities on T1-weighted (T1W) and T2-weighted (T2W) images for 52 cases were categorized into 3 types. Type 1 (20 cases) showed low signal intensities on T1W images and hyperintensity on T2W images. Type 2 (10 cases) showed hyperintensity on both T1W and T2W images. Type 3 (22 cases) showed hypointensity on T2W images.

A significantly higher proportion of patients with type 1 signal intensities had large cysts compressing their third ventricle than patients with the other 2 types of signal intensities. Patients with type 1 signal intensities also frequently had visual disturbances. Anterior pituitary dysfunction was observed more often in patients with type 2 or 3 signal intensities than in patients with type 1 intensities.

We conclude that Rathke cleft cysts that show an MR signal intensity similar to that of cerebrospinal fluid grow slowly and are frequently diagnosed as cysts associated with visual disturbance when they become large. It may be possible to predict the clinical progression of Rathke cleft cysts by assessing MR signal intensities.