Case Report: NET of the ear- up to date in diagnostic and therapeutic challenges

Neuroendocrine tumors (NET) usually originate from the gastro-entero-pancreatic or pulmonary tract. However, with the improvement of diagnostic techniques, the identification of NET arising in unusual origins is increasing, including the middle ear, but little is known about their management. We present three cases of NET of the middle ear (MeNET), with a special focus on histological diagnosis, radiological, and nuclear medicine imaging. We describe the surgical intervention performed and the systemic treatment used in one case of metastatic disease. We also conducted a review of the published cases, collecting data only on well-differentiated MeNET, histologically characterized by the presence of glandular/epithelial and neuroendocrine cells, with specific immunohistochemistry features (Cytokeratins+, Cromogranin A+, Synaptophysin +, enolase +, INSM1+). Our case series and literature review analysed the main clinical features, diagnostic challenges, and treatment response of this rare localization of NET, trying to provide a guide for the diagnosis and management of this rare disease.