Cystic hepatic lesions: No one imaging feature to rule them all

Presenter: Ryan Day MD | The University of Texas MD Anderson Cancer Center Background: Incidental cystic hepatic lesions are frequently diagnosed. Overlapping characteristics between hepatic cysts, premalignant biliary cystadenomas, and malignancies can lead to lengthy and exhaustive evaluations. The objective of this study was to examine clinical and imaging characteristics that distinguish between cystic hepatic lesions. Methods: Consecutive patients undergoing surgery for cystic hepatic lesions at a single institution between 2002 and 2017 were analyzed. Pre- and postoperative imaging reports and films were reviewed. Comparisons between patients with a pathologic diagnosis of hepatic cysts vs. biliary cystadenomas (BCA) were performed using the Chi-square or Mann-Whitney test. Results: Thirty-five patients underwent surgery for hepatic cysts (n=22), BCA (n=12), and echinococcal cyst (n=1). Preoperative diagnoses were correct in 68% and 42% of patients with hepatic cysts and BCA, respectively. Fourteen patients underwent preoperative biopsy and/or cyst fluid aspiration, which yielded a correct diagnosis in 7 patients (50%). Patients with BCA were more likely to have undergone preoperative biopsy and have a solitary lesion with a segment 4 predilection (Table). Imaging characteristics associated with BCA were septation, peripheral wall enhancement, and internal enhancement. These imaging features were also identified in hepatic cysts that were hemorrhagic (n=5) or infected (n=1). Three patients with BCA developed disease recurrence after fenestration. One patient developed biliary cystadenocarcinoma after prior R2 resection, underwent re-resection, and remains free of disease. Conclusion: Differentiating BCA from hepatic cysts is challenging due to overlapping imaging characteristics, particularly with hemorrhagic and infected cysts. Patients with indeterminate lesions may benefit from short-term interval imaging before choosing a surgical strategy or continued surveillance.