DIFFERENTIATING CYSTIC LIVER LESIONS USING CONTRAST-ENHANCED ULTRASOUND: A REPORT OF TWO CASES

Although simple liver cysts are common, cystic liver lesions often present diagnostic challenges, particularly in differentiating benign from malignant or precancerous conditions. Conventional imaging modalities such as Computed Tomography (CT) or Magnetic Resonance Imaging (MRI) may be insufficient for accurate diagnosis. Contract-enhanced ultrasound (CEUS) has emerged as a valuable tool for the evaluation of these lesions. Case Presentations: We report two cases of cystic liver lesions evaluated using CEUS. Case1: An 80-year-old woman with an asymptomatic hepatic cyst followed up for 3years was referred for evaluation of a neoplastic lesion. CT revealed a 50mm lesion in the right hepatic lobe cyst with ill-defined margins and irregular enhancement. CEUS demonstrated persistent sonazoid enhancement without washout, suggestive of a hemorrhagic cyst. A right hepatectomy was performed for diagnosis and treatment. Pathological examination confirmed the presence of thrombotic changes caused by hemorrhage, with partial organization and evidence of neovascularization. Case2: A 50-year-old woman presented with a lesion suspected to be intrasuctal papillary neoplasm of the bile duct (IPNB). CEUS revealed a 40mm-tumor with early hyperenhancement and late mild washout of sonazoid in a right hepatic lobe cyst, rasing suspicion of malignancy. Surgical resection was mandatory for the optimal management of this tumor. A fenestration, including fenestration and partial liver resection, was performed. Pathological findings confirmed IPNB with carcinoma in situ, underscoring the malignant potential of this lesion. CEUS provides critical insights into the vascular characteristics of cystic liver lesions. In these cases, CEUS enabled accurate preoperative assessment and informed surgical decision-making. These findings highlight the potential of CEUS as a reliable diagnostic and management tool for cystic liver lesions. Our findings suggest that CEUS is useful not only for distinguishing between benign and malignant lesions but also for diagnosing precancerous conditions.