Unusual imaging appearances of pancreatic serous cystadenoma: correlation with surgery and pathologic analysis

We describe imaging and pathologic features of serous cystadenoma of the pancreas on multislice helical computed tomography CT (MS-CT) and surgical resection.

Radiologic and pathologic features were analyzed in five patients. All patients underwent MS-CT and digital subtraction angiography (DSA), and four patients underwent magnetic resonance (MR) imaging. Preoperatively, three cases showed radiologic evidence of mainly solid appearance on MS-CT, and the suspected diagnoses were solid pancreatic tumors (patients 1-3). The other two cases showed radiologic evidence of macrocystic tumor of the pancreas, and the suspected diagnoses were mucinous cystic tumors (cases 4 and 5). All patients underwent surgery, and the diagnosis of serous cystadenoma was confirmed on pathologic examination.

In three cases that showed a solid appearance on MS-CT, a microcystic appearance was identified on microscopic examination, and the tumors were found to be hypervascular lesions on multiphasic contrast-enhanced CT and DSA. In cases 1 and 2, the lesions showed high intensity with internal septation on T2-weighted MR images. In two cases, the tumors were classified as a macrocystic variant of serous cystadenoma, and no mural nodules, papillary projections, or calcifications were seen in the tumors.

Imaging appearance of serous cystadenoma on MS-CT is various and sometimes indistinguishable from that of solid tumor or mucinous cystic tumors of the pancreas. Imaging findings of hypervascularity and a well-marginated high-intensity lesion with internal septation on T2-weighted MR imaging may be crucial to identify serous cystadenoma that contains no visible cystic compartments on MS-CT.