IMAGING FEATURES OF CILIATED HEPATIC OR B ILIARY CYSTS - 4 CASES

Four patients with ciliated hepatic cysts, a rare and benign lesion, w ere examined between 1990 and 1994. Imaging features were compared to 12 previous cases. All lesions were revealed by US, and were hypoechoi c in 3 cases, and anechoic in 1 case. All lesions were less than to 4 cm in diameter, and were well-defined, unilocular, isolated, and locat ed in subcapsular areas, usually in the medial segment of the left lob e of the liver (3 cases). In one case, the cyst was found in the gallb ladder wall. The lesions were low density on pre- and post-contrast CT scan (performed in 2 cases), strongly hyperintense on T2-weighted MR images (2 cases), and had a variable signal intensity on T1-weighted M R images. One patient underwent percutaneous guided biopsy but no diag nosis was obtained. None of the patients had preoperative diagnosis an d all underwent surgery. Diagnosis was confirmed by histopathologic ex amination of the resected specimen. Ciliated hepatic cysts may be susp ected in this study and in the literature. Diagnostic criteria are as follows: hypoechogenic mass less than 4 cm in diameter, located in the subcapsular area of the medial segment of the left lobe of the liver.