Summary of changes including deletion, addition, and reclassification of SNT tumors in the 5th edition of the WHO Classification 2022
| WHO Classification 4th Edition 2017 (Chapter 1) | WHO Classification 5th Edition 2022 (Chapter 2) | |
|---|---|---|
| Respiratory epithelial lesions | Hamartomas (new category) | |
| REAH | REAH | |
| Seromucinous hamartoma (new entity in 4th edition) | Seromucinous hamartoma | |
| Nasal chondromesenchymal hamartoma (reclassification from “other” category) | ||
| Sinonasal papillomas | Subcategory under respiratory epithelial lesions in 5th edition (2022) | Respiratory epithelial lesions (includes papillomas, carcinomas, adenocarcinomas with removal of hamartomatous lesions) |
| Sinonasal papillomas | ||
| Carcinomas | Subcategory under respiratory epithelial lesions in 5th edition(2022) | Carcinomas |
| Keratinizing SCCa | Keratinizing SCCa | |
| Nonkeratinizing SCCa | Nonkeratinizing SCCa (includes emerging entity DEK-AFF2 carcinoma) | |
| Spindle cell (sarcomatoid) SCCa | NUT carcinoma | |
| Lymphoepithelial carcinoma | SWI/SNF complex-deficient sinonasal carcinoma (new entity) | |
| Sinonasal undifferentiated carcinoma | Sinonasal lymphoepithelial carcinoma | |
| NUT carcinoma (new entity in 4th edition) | Sinonasal undifferentiated carcinoma (includes emerging entity IDH-mutated carcinoma) | |
| Neuroendocrine carcinoma | Adenocarcinomas separated as a new subcategory | Teratocarcinosarcoma |
| Adenocarcinoma | HPV-associated multiphenotypic sinonasal carcinoma (new entity) | |
| Intestinal-type adenocarcinoma Non–intestinal-type adenocarcinoma | Adenocarcinomas (new subcategory, was previously under carcinomas) | |
| Intestinal-type sinonasal adenocarcinoma Non-intestinal-type sinonasal adenocarcinoma | ||
| Malignant soft-tissue tumors | Categories removed with dedicated chapters on soft-tissue tumors in the new edition | Mesenchymal tumors of the SNT (new category with few retained entities from soft-tissue tumors, occurring exclusively or primarily in the SNT) |
| Borderline/low-grade malignant soft-tissue tumors | SNT angiofibroma | |
| Benign soft-tissue tumors | Sinonasal glomangiopericytoma | |
| Neuroectodermal/melanocytic tumors | Biphenotypic sinonasal sarcoma | |
| Hematolymphoid tumors | Chordoma | |
| Other tumors | Sinonasal ameloblastoma | |
| Meningioma | Adamantinomatous craniopharyngioma (reclassified from chapter on “nasopharynx”) | |
| Sinonasal ameloblastoma | Meningioma of the SNT, ear | |
| Chondromesenchymal hamartoma (moved to hamartomas) | Olfactory neuroblastoma | |