RATHKE CLEFT CYST - CT, MR, AND PATHOLOGY OF 23 CASES

Objective: We report the radiologic findings in 23 cases of Rathke cleft cyst (RCC) and correlate them with the histopathology. Materials and Methods: We reviewed the radiology and pathology of 23 cases of surgically treated RCC operated upon at our institution or referred in consultation. Results: There appears to be a correlation between the MR and CT appearance of the cyst, the gross appearance of the cyst contents, and the histopathologic characteristics of the cyst lining. Some of the lesions demonstrated peripheral enhancement, which in two cases was clearly due to a peripherally displaced rim of pituitary tissue. Conclusion: The appearance of RCC with CT and MRI is variable, and radiologic diagnosis can be difficult. Imaging features such as a sellar epicenter, smooth contour, absence of calcification, absence of internal enhancement, and homogeneous attenuation or signal intensity within the lesion suggest the diagnosis of RCC. Rim enhancement does not correlate with the presence of squamous metaplasia, hemosiderin, or cholesterol within the cyst wall and is not consistently seen in cases with changes of mild, chronic inflammation. In some cases, rim enhancement is due to a peripherally displaced rim of pituitary tissue.