SMARCB1 (INI-1)-Deficient Sinonasal Carcinoma: A Case Report and Literature Review.

SWItch/Sucrose Non-Fermentable related matrix-associated actin-dependent regulator of chromatin subfamily B member 1 (SMARCB1)-deficient sinonasal carcinoma (SDSC) is a malignant tumor classified as sinonasal undifferentiated carcinoma (SNUC). Owing to the high aggressiveness and poor prognosis reported in recent literature, patients diagnosed with SNUC should consider further immunohistochemical examination to screen for SDSC. Timely diagnosis is critical and will contribute to follow-up targeted therapy and improved patient prognosis. Case report. A case of SDSC with a history of chronic sinusitis with nasal polyps (CRSwNP). We collected all the clinical data of this patient. The patient underwent planned functional endoscopic sinus surgery (FESS) and received chemotherapy combined with immunotherapy postoperatively. There was no evidence of recurrence or metastasis at the 3-month follow-up. The patient in this case presented with right intermittent epistaxis, and surgical histopathological examination confirmed a diagnosis of right SDSC and left CRSwNP. No related research has been reported.