Multimodal imaging features of primary hepatic malignant perivascular epithelioid cell tumor: A case report

Perivascular epithelioid cell tumors (PEComas) of the liver are rare mesenchymal neoplasms with heterogeneous biological behavior, and malignant hepatic PEComas are particularly uncommon, aggressive, and associated with an unpredictable prognosis. Preoperative diagnosis remains challenging due to nonspecific clinical manifestations and laboratory findings, and comprehensive analyses of multimodality imaging features are limited. We report a case of a 56-year-old woman without liver cirrhosis who was incidentally found to have a hepatic mass during routine physical examination. Ultrasound, contrast-enhanced ultrasound (CEUS), CT, and MRI revealed a large cystic-solid lesion in the right hepatic lobe with intratumoral hemorrhage, characterized by a fluid-fluid level on T2-weighted imaging. Arterial-phase imaging demonstrated abnormally thickened intratumoral vessels, while the solid components showed persistent delayed enhancement with pseudocapsule formation. CEUS revealed slow washout in the delayed phase, with subtle differences compared with CT and MRI enhancement patterns. Based on multimodality imaging findings, a hepatic mesenchymal tumor with high malignant potential was suspected, and right hepatic lobectomy was performed. Histopathological and immunohistochemical examination confirmed primary malignant hepatic PEComa. No metastasis or recurrence was observed during follow-up. This case highlights that multimodality imaging may provide important clues for assessing malignant potential and should prompt consideration of malignant PEComa in the differential diagnosis of hepatic cystic-solid lesions.