A locus-specific loss of heterozygosity in the PEComa but not in the sinonasal carcinoma was identified, suggesting the causative role of the splice mutation in the PEComa pathogenesis, because we excluded known pathogenetic pathways characteristic to PEComas (<i>TSC1/2</i>, <i>TFE3</i>, <i>RAD51B</i>). Here, TFE3 is linked to neoplasm with perivascular epithelioid cell differentiation.