Is Epithelioid Hemangioendothelioma a Cold Tumor for Immune Check Point Inhibitors? A Case Report

Epithelioid Hemangioendothelioma (EHE) is a rare malignant vascular neoplasm. We herein report a rare pulmonary EHE case and consider the potential treatment target. A 55-year-old male patient with bilateral multiple pulmonary nodules underwent partial resection of the lung to obtain a definitive diagnosis, and the diagnosis of EHE was made. Since EHE is a chemotherapyresistant tumor, we analyzed the molecular expression related to tumor immunity and hormone receptors by Immunohistochemistry (IHC). Major Histocompatibility Complex (MHC) class I and PD-L1 molecules in the tumor were significantly attenuated, and lymphocytes, CD8 T cells, and tumor-specific CD103-positive lymphocytes were scarcely observed in the tumor. Neither estrogen receptor nor progesterone receptor was expressed on tumor cells. The patient did not wish to be treated aggressively. Although our data revealed that neither immune checkpoint inhibitors nor hormonal therapy for pulmonary EHE could be expected to be effective, further analyses using more EHE cases are necessary to consider the potential treatment target for EHE.