SMARCB1 and malignant peripheral nerve sheath tumor: Immunohistochemical loss of the SMARCB1/INI1 protein expression has been described in myoepithelial carcinomas and renal medullary carcinomas, in a subset of malignant peripheral nerve sheath tumors and of extraskeletal myxoid chondrosarcomas as well as in ES of both distal and proximal type.