Update from the 5th Edition of the World Health Organization Classification of Head and Neck Tumours: Tumours of the Ear

Abstract

In the recently published 5th Edition of the World Health Organisation Classification of Head and Neck Tumours, there are relatively few changes to report in terms of nomenclature in lesions of ear and temporal bone and fewer developments in molecular pathogenesis in comparison to other sites, particularly in sinonasal tract. Ear and temporal bone tumours are rare and biopsy material is limited. As a result, resources in the literature are scarce with few large series, no controlled clinical trials and the approaches to staging and management are not standardised. New entities are difficult to characterise. The number of entries has, however, increased for tumours of the ear and temporal bone (thirteen) compared to the 4th Edition (eleven). Some lesions previously included in the 4th Edition considered to have no site-specific features have been excluded to be discussed elsewhere and other benign lesions that are specific to this site have been included. The tumours and tumour-like entities of ear and temporal bone are discussed here mindful that the chapter in the 5th edition better correlates disease processes with clinical information and imaging and as far as possible standardises nomenclature.

Immunohistochemical Expression Pattern of Theragnostic Targets SSTR2 and PSMA in Endolymphatic Sac Tumors: A Single Institution Case Series

“…Paragangliomas and meningiomas strongly express SSTR2 on tumor cells, providing a rationale for the binding and accumulation of SSTR targeting agents such as DOTATATE [ 28 , 29 ]. Middle ear adenoma, currently renamed as middle ear neuroendocrine tumor (MeNET) [ 30 ], usually show neuroendocrine differentiation and SSTR expression is indicated by positive octreotide scan [ 31 ]. Furthermore, high uptake on 68 Ga-DOTATOC PET/CT followed by effective peptide receptor radionuclide therapy (PRRT) was reported [ 32 ].…”

Malignant tumors of the external auditory canal: diagnosis, treatment, genetic landscape, biomarkers, and clinical outcome

“…Thus, the International Collaboration on Cancer Reporting (ICCR) has produced standardized and evidence-based data sets for various organs, including the ear and temporal bone. The data set provides guidelines for the reporting of the biopsy and the resection specimens, elements required for stage, prognosis, and treatment [6].…”

“…The 5th Edition of the World Health Organization Classification of Head and Neck Tumors: tumors of the ear discusses the tumors and tumor-like entities of the ear and temporal bone [ 7 ]. It correlates disease processes with clinical information and imaging, and highlights histological features and advances in the understanding of the molecular pathogenesis of these lesions [ 7 ].…”

“…Firstly, an EAC malignancy should be differentiated from the various benign tumors of the area including cystic chondromalacia and chondrodermatitis nodularis chronica helicis of the external ear, exostosis or osteoma, pleomorphic adenoma, syringocystoma papillferum and adenoma not otherwise specified (NOS) [ 7 ]. Moreover, vascular tumors and malformations of the EAC have also been defined, with otoscopy not being always sufficient for their characterization.…”

“…Histological examination of the resection samples may be tricky due to the complex anatomy of the area. Similar practices could be employed for other tumors arising in the same site and requiring surgical involvement, besides SCC [ 7 ].…”