Radiologic Reporting of Simple Hepatic Cyst Versus Biliary Cystadenoma May Lead to Unnecessary Surgery

Abstract

Background and aims: Simple liver cyst (SHC) is a benign condition with no malignant potential. They are typically discovered incidentally due to the increased use of abdominal imaging, but some patients may present with abdominal pain. A radiologist's differential diagnosis in cases of SHC will often include "rule out biliary cystadenoma." Under these circumstances, patients and surgeons are more likely to pursue surgical options even in asymptomatic cases. The aim of this study is to conduct a retrospective analysis of presentation, radiologic reporting, management plan, and histopathology of patients referred to a tertiary hospital in order to determine the correlation between radiology and histology.

Methods: We retrospectively analyzed the clinical, radiological, and histopathological data of 20 patients operated for a diagnosis of a cystic lesion in the liver.

Result: The CT/MRI of 6 (30%) patients was reported as a biliary cystadenoma, 13 (65%) were reported as a simple hepatic cyst and 1 patient (5%) had hepatocellular carcinoma (HCC) with the additional diagnosis of multiple hepatic cysts. The lesion reported as HCC on the scan was separate from the cystic lesions. The modality of imaging for these cysts was evenly split, 50% of patients had a CT scan, and 50% had an MRI performed. All imaging studies were interpreted by an attending radiologist and most of them were discussed in multidisciplinary meetings. Nineteen patients (95%) had an intraoperative diagnosis of a simple liver cyst based on its visual appearance and clear fluid within the cyst. These patients underwent cyst wall fenestration and de-roofing with the cyst wall sent for histopathology. One patient (5%) with HCC underwent a non-anatomical liver resection. Histopathology was conclusive for a benign hepatic cystic lesion from the cyst wall biopsy. All 20 patients in this study underwent surgery, either due to symptoms or due to radiologic diagnosis of BCA. Four of the 20 cases (20%) were asymptomatic and out of these four cases, 3 (75%) were diagnosed as cystadenoma on the preoperative imaging studies. All 19 cases were diagnosed as a simple liver cyst on pathology.

Conclusion: In summary, there is a growing trend of "ruling-out the diagnosis of biliary cystadenoma" in patients who present with liver cysts. Patients are appropriately more anxious after this preoperative diagnosis and the treating surgeons have medico-legal concerns regarding conservative management in asymptomatic patients diagnosed as BCA. This single center experience draws attention to the radiology criteria utilized for diagnosing a biliary cystadenoma and suggests that it is time to revisit the imaging interpretation and differential diagnosis.

Keywords: biliary cystadenoma; liver cyst; lobulation; malignant; septation; simple hepatic cyst.