Biphenotypic Sinonasal Sarcoma

**Semantic type:** Neoplastic Process

**Definition:** A rare, slow-growing, low-grade soft tissue sarcoma arising from the sinonasal tract. It presents with non-specific obstructive nasal symptoms. Morphologically, it is an infiltrative, cellular spindle cell neoplasm. It is associated with rearrangement of the PAX3 gene.

**Synonyms:** - BSNS - Biphenotypic sinonasal sarcoma - Low Grade Sinonasal Sarcoma with Neural and Myogenic Differentiation - Low-Grade Sinonasal Sarcoma with Neural and Myogenic Differentiation - Sinonasal Biphenotypic Sarcoma