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