Sinonasal teratocarcinosarcoma involving the nasal cavity, unilateral paranasal sinuses, and intracranial invasion: A case report.

Background: Sinonasal teratocarcinosarcoma (SNTCS) is a rare and highly invasive neoplasm originating from the nasal cavity and sinuses. Typically, it exhibits an invasive behavior towards adjacent structures; however, in exceptional instances, it may infiltrate the intracranial compartment. Due to the tumor's rarity and lack of distinctive features on computed tomography (CT) and magnetic resonance imaging (MRI) images, SNTCS is often misdiagnosed.