Rare benign liver tumors that require differentiation from hepatocellular carcinoma: focus on diagnosis and treatment

Recently, an increase in the number of asymptomatic rare benign liver tumors (BLTs) has been reported during health check-ups. It is difficult to determine the nature of partial rare BLTs and not easy to distinguish from malignant liver tumors. This study aimed to analysis clinical features, diagnosis and treatment of rare BLTs to reduce misdiagnosis and provide reference for clinical practice.

From January 2012 to January 2021, we treated 112 rare BLTs by hepatectomy, including 54 focal nodular hyperplasias, 14 hepatocellular adenomas, 28 hepatic angiomyolipomas, 3 hepatic granulomas, 2 inflammatory pseudotumors of the liver, 2 nodular regenerative hyperplasia, 2 hepatic lipomas, 1 solitary fibrous tumor of the liver, 1 hepatic schwannoma and 1 hepatic myelolipoma.

The majority of patients were middle-aged female and asymptomatic. Single tumors were dominant. The diagnostic accuracies of computed tomography (CT) and magnetic resonance imaging (MRI) were 32.5% and 44.2%, respectively. The majority of tumors were likely to be misdiagnosed as hepatocellular carcinoma (HCC) or difficult to distinguish from HCC. All patients underwent surgical treatment. Postoperative pathological and immunohistochemical examination can confirm the diagnosis. No patients without tumor recurrence or metastasis during follow-up period.

Altogether, the clinical symptoms of rare BLTs lack specificity, and their preoperative diagnosis largely depends on imaging examination, with a low diagnostic accuracy rate and high chances of misdiagnosis as HCC. Diagnosis is confirmed by pathological and immunohistochemical examination. Surgical resection for rare BLT is safe and effective, regular postoperative follow-up is necessary.