Hepatobiliary cystadenoma

Panel A: Ultrasound shows a large cystic lesion with septations and slightly irregular wall. Panel B: CT scan demonstrates the same cyst occupying most of the left hepatic lobe. Panel C: Histologic appearance: Low power magnification showing the wall of the cyst composed of a layer of loose vascular, spindle cell stroma lined by tall columnar epithelium. Note polypoid projections (hematoxylin and eosin, original magnification: x 400). Panel D: Closer view demonstrates the layer of simple columnar epithelium with focal areas of pseudostratification. No cellular atypia or pleomorphism is noted (hematoxylin and eosin, original magnification: x 2000).