SMARCB1-Deficient Sinonasal Carcinoma–A Case Report and Literature Review

Abstract

Switch/sucrose non-fermentable-related matrix-associated actin-dependent regulator of chromatin subfamily B member 1 (SMARCB1)-deficient sinonasal carcinoma is a rare subtype of sinonasal undifferentiated carcinoma (SNUC). Due to the highly aggressive nature of the disease course, it is important to diagnose early and use multimodal treatments in the course of the disease. Two main morphologic patterns are commonly identified under the microscope: plasmacytoid/rhabdoid and basaloid. Furthermore, it demonstrates a total absence of integrase interactor 1 expression upon immunohistochemical staining. Here, we present two cases of SMARCB1-deficient sinonasal carcinoma with contrasting outcomes.