SMARCA4 and nasal cavity and paranasal sinus carcinoma: <b>Methods</b>: We designed a retrospective single-center case series to analyze the clinicopathological features of 17 patients with SMARCB1-deficient sinonasal carcinoma (<i>n</i> = 10), SMARCA4-deficient carcinoma (<i>n</i> = 6) and SMARCA4-deficient sinonasal teratocarcinosarcoma (TCS) (<i>n</i> = 1) treated between 2018 and 2025, and reviewed the relevant literature.