Table 2.

Sinonasal tumors reviewed in this article: Immunohistochemical features and molecular genetic data

Tumor type	Immunohistochemistry	Molecular genetics
Respiratory epithelial lesions – carcinomas
Non-keratinizing squamous cell carcinoma	CK, p63/p40, CK5/6, p16	HPV association (20–62%),
		Type 16
		EBV association – rare
		subset DEK::AFF2
NUT carcinoma	NUT, p63, CD34	NUTM1::BRD4/BRD3/NSD3/ (ZNF532, ZNF592)
SWI/SNF complex-deficient sinonasal carcinoma
SMARCB1 deficient carcinoma	CK5, p63, CK7, SMARCB1-loss	SMARCB1 mutation ± SMARCA2 mutation
SMARCB1 deficient adenocarcinoma	CK7, p40, glypican 3, SALL4, HepPar-1, CDX2, CK20, PLAP and AFP; SMARCB1-loss	SMARCB1 mutation
SMARCA4 deficient carcinoma	CK, CK7, synaptophysin. Chromogranin, CD56; SMARCA4 loss	SMARCA4 mutation ± SMARCA2 mutation
Sinonasal lymphoepithelial carcinoma	EBV	EBV
Sinonasal undifferentiated carcinoma (SNUC)	diagnosis per exclusionem, a subset IDH1/2	IDH wild type and IDH1/2 mutations
HPV-associated multiphenotypic sinonasal carcinoma	Biphasic, S100, SOX10, p16	HPV – mainly serovariety 33

Excluded entities without diagnostic molecular genetic characteristics

Adapted from:

WHO Classification of Tumours Editorial Board. Head and neck tumours. Lyon (France): International Agency for Research on Cancer; forthcoming. (WHO classification of tumours series, 5th ed.; vol. 9). https://publications.iarc.fr