Neuroendocrine neoplasms of the middle ear: Unpredictable tumor behavior and tendency for recurrence

Background Middle ear adenomatous neuroendocrine tumors (MEANTs) are rare temporal bone tumors. This study evaluates its clinical behavior and therapy outcome. Method Retrospective case review in a tertiary referral center evaluating histopathology, immunohistochemistry, treatment, and outcome. Results Nine patients were diagnosed with MEANT. One patient presented with locally invasive tumor and underwent extensive en-bloc tumor resection with adjuvant radiotherapy. Seven of eight patients with locally non-aggressive tumor confined to the tympanomastoid space underwent tumor resection. Two patients were disease-free, five presented recurrence, even after apparent successful surgery. All tumors showed neuroendocrine features. Histopathology and immunohistochemistry did not yield prognostic tumor characteristics. Conclusion MEANTs are rare tumors with uncertain biological behavior and subsequent unpredictable clinical course. The preferred treatment is complete surgical tumor resection. They have a high tendency for recurrence, irrespective of negative intermediary surgery. As of yet, there are no prognostic biomarkers, including histopathology and immunohistochemistry.