Penile pseudomyogenic hemangioendothelioma/epithelioid sarcoma-like hemangioendothelioma with a novel pattern of SERPINE1-FOSB fusion detected by RT-PCR--report of a case.
We previously identified characteristic FOSB expression in pseudomyogenic hemangioendothelioma (PHE) with a specific SERPINE1-FOSB fusion, revealing the usefulness of FOSB immunohistochemistry in the differential diagnosis of PHE and its mimics.
Interestingly, in FOSB overexpressing cells, telatinib specifically affected PDGFRA, FLT1, and FLT4 signaling and downregulated SERPINE1, thereby affecting the self-regulation of the fusion gene.<b>Conclusions:</b> We provide a biological substantiation of a complete clinical remission that was seen in a patient with PHE, showing that telatinib indirectly interferes with the self-regulated expression of the fusion product.
Recurrent SERPINE1-FOSB gene fusions have been reported as the hallmark genetic abnormality in PHE, however, in our experience, a number of cases with typical histology lack this genetic abnormality.