Polycystic Liver Disease with a Large Intracystic Papillary Projection: Image-Pathologic Correlation

Complicated cysts are not uncommon in patients with polycystic liver disease (PCLD) but prominent papillary projection within the cyst rarely occurs which may mimic malignant transformation, especially when there is progressively elevated serum tumor markers. We described such an unusual presentation in a patient with PCLD who had fever, diarrhea, and progressive elevated serum CA 19-9 and CEA. The imaging findings reflected the pathologic features of the papillary projection in a complicated cyst, featuring predominant fibrous stroma and some small bile ducts which appeared as sonographically anechoic tiny cystic spaces. These small bile ducts were consistent with hyperintense dots on T2-weighted magnetic resonance (MR) images. The findings suggested bile duct origin of the papillary projection. The clinical symptoms disappeared after operation. Familiarity with these imaging findings may be helpful in making differential diagnosis preoperatively.