CT and MRI features differentiating mucinous cystic neoplasms of the liver from pathologically simple cysts

The purpose of this study was to determine if CT and MRI features can accurately differentiate mucinous cystic neoplasms (MCNs) from simple liver cysts and to compare accuracy of CT and MRI in detecting these features.

Eighty-four surgically treated lesions with pre-operative CT or MRI were evaluated by two abdominal radiologists for upstream biliary dilatation, perfusional change, internal hemorrhage, thin septations, thick septations/nodularity, lobar location, and number of coexistent liver cysts. Odds ratios, sensitivities, specificities, and positive and negative predictive values were calculated for association of each feature with MCNs.

Of 84 liver lesions, 13 (15%) were MCNs, all in women, and 71 (85%) were simple cysts, in 59 women and 12 men. Thick septations/nodularity, upstream biliary dilation, thin septations, internal hemorrhage, perfusional change, and fewer than 3 coexistent liver cysts were more frequent in MCNs than in simple cysts. The combination of thick septations/nodularity and at least one additional associated feature showed high specificity for MCNs (94-98%). MRI detected significant associations of biliary dilation, thin septations, and hemorrhage/debris with MCNs which CT did not.

Surgically treated MCNs of the liver with preoperative imaging occurred at our institution only in women. Thick septations or nodularity, biliary dilation, thin septations, internal hemorrhage or debris, perfusional change, and fewer than 3 coexistent liver cysts are features that help differentiate MCNs from simple cysts. MRI has advantages over CT in detecting these features.