[Serous cystadenoma of the pancreas: imaging findings]

To present the imaging findings of serous cystadenoma (SCA) and discuss the main problems of differential diagnosis with other cystic pancreatic lesions.

55 cases of SCA were reviewed; all the lesions proved to be benign at pathology. 35 tumors were evaluated with Ultrasonography (US), 49 with Computed Tomography (CT), and 15 with Magnetic Resonance Imaging (MRI).

Among the patients who underwent either demolitive (47) or derivative (3) interventions, two different morpho-structural patterns were identified: microcystic (37), and oligocystic (13). The diagnosis of SCA, possible in the presence of microcystic pattern, was achieved in 63% of cases by US (22/35), in 63% of cases by CT (31/49), and in 73% of cases by MRI (11/15). In 12 patients evaluated with all the imaging modalities, the combined information allowed a correct diagnosis in 10 cases (83%). The 13 oligocystic tumors were almost always undistinguishable from other cystic masses of the pancreas.

The diagnosis of SCA can be considered certain if a microcystic pattern is detected. A correct diagnosis is not achievable in the presence of oligocystic architecture. MRI is the best imaging modality in characterizing this tumor.