Activity of lenalidomide in metastatic hepatic epithelioid hemangioendothelioma (HEH): A case report

e21527 Background: HEH is a rare tumor of the liver with an unpredictable malignant potential. Surgical resection or liver transplantation is recommended in locally advanced disease and has been successfully performed in selected cases with extrahepatic manifestations. Systemic therapy, however, is not standardized. Small cohorts have been treated with interferon, chemotherapy and angiogenesis inhibitors such as thalidomide with various results. Case report: A 33-year old caucasian previously healthy male was admitted to hospital with newly diagnosed suspicious lesions in liver and spleen. Further analyses showed additional pulmonal nodules. Biopsy revealed a tumor with predominant epithelioid cells, positive for CD31 and CD34 and negative for CD117, HHV8, AFP and CEA, classified as a HEH. Disease progressed during first line treatment with adriamycin and ifosfamide (2 cycles given). Based on a case report with encouraging results with thalidomide we treated our patient with lenalidomide, which is known to have less side effects while being more effective in the myeloma setting. After 6 courses of lenalidomide 25mg daily (21/28), regression of the splenic lesions was detected. Retrospective analysis after 9 cycles demonstrated stable disease in comparison to the recent investigation, but an overall progression of 22% according to RECIST criteria in the liver was observed. Due to the excellent tolerance we increased the daily dose to 30 mg (21/28) and 6 months later a slight regression in the lung and overall stable disease in the liver was observed. The splenic lesion disappeared completely. The patient was listed for liver transplantation and after another 4 months on lenalidomide 30 mg, he was successfully transplanted recently. Because of the remaining extrahepatic lesions it is planned to continue lenalidomide therapy in combination with the immunosuppressant rapamycine. Conclusions: We report the first case of successful therapy with lenalidomide in HEH. Higher doses than 25mg seem to be more effective. We grateful thank Celgene for offering us lenalidomide for this off label use. No significant financial relationships to disclose.