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

Objective: We report the radiologic findings in 23 cases of Rathke cle ft cyst (RCC) and correlate them with the histopathology. Materials an d Methods: We reviewed the radiology and pathology of 23 cases of surg ically treated RCC operated upon at our institution or referred in con sultation. Results: There appears to be a correlation between the MR a nd CT appearance of the cyst, the gross appearance of the cyst content s, and the histopathologic characteristics of the cyst lining. Some of the lesions demonstrated peripheral enhancement, which in two cases w as clearly due to a peripherally displaced rim of pituitary tissue. Co nclusion: The appearance of RCC with CT and MRI is variable, and radio logic diagnosis can be difficult. Imaging features such as a sellar ep icenter, smooth contour, absence of calcification, absence of internal enhancement, and homogeneous attenuation or signal intensity within t he lesion suggest the diagnosis of RCC. Rim enhancement does not corre late with the presence of squamous metaplasia, hemosiderin, or cholest erol within the cyst wall and is not consistently seen in cases with c hanges of mild, chronic inflammation. In some cases, rim enhancement i s due to a peripherally displaced rim of pituitary tissue.