Microwave Ablation and Transcatheter Arterial Chemoembolization for Hepatic Epithelioid Hemangioendothelioma Two Case Reports

Background: Hepatic epithelioid hemangioendothelioma (HEHE) is a rare vascular sarcoma in which surgery or liver transplantation is often not feasible due to multifocal or unresectable disease. For these patients, standardized treatment protocols are lacking, and the long-term efficacy of non-surgical options has been limited. Consequently, there is limited data on durable, minimally invasive treatment strategies. This report presents the long-term outcomes of two distinct, minimally invasive treatment strategies—staged microwave ablation (MWA) and MWA combined with transcatheter arterial chemoembolization (TACE), highlighting their potential as durable treatment options for unresectable HEHE. Case Description: We describe two patients with pathologically confirmed, unresectable HEHE who achieved sustained complete response (CR). Case 1, a 47-year-old female with multifocal HEHE that had progressed despite prior systemic therapies, underwent staged MWA. After 40 months of follow-up, she maintained CR as assessed by mRECIST criteria. Case 2, a 53-year-old male, presented with multiple large and confluent lesions, the largest being 6.9 cm in diameter. He was treated with a combination of TACE and MWA. At an 84-month follow-up, he also remained in CR with significant tumor reduction and no signs of recurrence. Neither patient experienced serious treatment-related complications. Conclusions: For patients with unresectable HEHE, MWA appears to be a safe option that offers durable disease control. This report supports a staged MWA approach for multifocal lesions and a combined strategy with TACE for larger tumors. These findings highlight the emerging role of interventional therapies in the contemporary treatment paradigm of this rare hepatic sarcoma.