✅ Pseudomyogenic hemangioendothelioma 🎯🩸
• Composed of sheets and fascicles of spindled to epithelioid cells with dense, myoid-like eosinophilic cytoplasm.
• Tumors co-express keratins and vascular markers like FLI1 and ERG (but are often negative for CD34).
• Characterized by FOSB gene rearrangements (e.g., SERPINE1::FOSB).
• This is a rarely metastasizing endothelial neoplasm that often mimics a myoid tumor or epithelioid sarcoma.
ALT Infiltrative tumor involving dermis and subcutis @IARCWHO
ALT
Tumor composed of sheets and fascicles of atypical spindled cells @IARCWHO
ALT
Diffuse expression of keratin @IARCWHO
ALT
Diffuse expression of ERG @IARCWHO