These include epithelial-derived neoplasms such as squamous cell carcinoma, with poorly differentiated carcinoma likely arising from inverted papillomas; sinonasal undifferentiated carcinoma (SNUC), for which induction treatment is the mainstay of initial treatment; SMARCB1-deficient sinonasal carcinoma; nasopharyngeal carcinoma; HPV-related carcinoma; and salivary/non-salivary type adenocarcinomas. Here, SMARCB1 is linked to sinonasal undifferentiated carcinoma.