Imaging and pathological analysis of a case of primary pseudomyogenic hemangioendothelioma at the proximal Femur
Pseudomyogenic hemangioendothelioma(PHE)is a rare intermediate vascular tumor originating from bone,which has been less reported in radiological studies.It was previously known as epithelioid sarcoma-like hemangioendothelioma(ES-HE).The tumor cells exhibit bright eosinophilic cytoplasm and morphologically resemble rhabdomyoblasts,while immunohistochemistry demonstrates endothelial differentiation.In the 2013 WHO classification of soft tissue and bone tumors,the term PHE was used.The tumor exhibits invasiveness,but metastasis is rare.It is classified as an intermediate vascular neoplasm.The 2020 classification maintains the same name and classification,and emphasizes the sensitivity of FOSB protein immunohistochemical staining in diagnosing PHE.Herein,we report the radiological findings of a surgically and pathologically confirmed case of primary bone PHE.In this case,the lesion was localized in the proximal femur and exhibited irregular lytic bone destruction with partial sclerotic borders.Residual bony trabeculae was visible internally,and consistent with the literature and characteristics of intermediate-type PHE with no periosteal reaction or cortical breakthrough.CT and MRI enhancement scans revealed significant enhancement in line with its vascular origin.MRI also showed minimal focal hemorrhagic signals,and the MRI low signal margin around the lesion extended wider than the CT sclerotic margin,which were consistent with the histological features of focal bleeding and iron-hemosiderin deposition.