Contemporary review of middle ear adenomatous neuroendocrine tumors.

PURPOSE OF REVIEW: To review the updated literature on middle ear adenomatous neuroendocrine tumors (MEANTS) and to discuss advances in classification, diagnosis, and management of these tumors.

RECENT FINDINGS: The WHO updated its classification of head and neck neuroendocrine neoplasms in 2022. We discuss this classification system, and its implications on the diagnosis of these tumors from a histological and molecular perspective. Furthermore, this framework helps with our understanding of their clinical course and hence management.

SUMMARY: In 2022, WHO classified head and neck neuroendocrine neoplasms into well differentiated neuroendocrine tumors (NET) (G1-G3, based on mitotic count/Ki67) and high-grade neuroendocrine carcinoma (NEC) (small/large cell), based on differentiation, atypia, and marker expression. Aside from histological characteristics, the WHO classification distinguishes NETs (site-specific epigenetic changes) from NECs (TP53/RB1 alterations). Small cell NECs show biallelic TP53/RB1 inactivation; large cell NECs are heterogeneous. Molecular profiling helps differentiate NET G3 from NEC. Recent reviews have shown higher rates of recurrence than previous studies, emphasizing the need for surgical modification based on tumor extent and biology, and for indefinite surveillance.