SMARCA4 and neoplasm: In this case, the tumor is mainly comprised of undifferentiated carcinoma of large round cells, cytologic features (undifferentiated tumor cells with slightly discohesive cells arranged in sheets and nests, abundant geographic necrosis), and immunohistochemical staining results (complete loss of both SMARCA4 and SMARCA2, reactivity of SALL-4) matching histopathology characteristics of SMARCA4-dUT.