Clinical Predilection Features of Middle Ear Adenomatous Neuroendocrine Tumors: A Review of 10 Patients and a Special Case Is Attached.

Introduction: Middle ear adenomatous neuroendocrine tumors (MEANTs) are rare middle ear lesions characterized by nonspecific symptoms, signs, and imaging findings. Diagnosis typically relies on postoperative pathological assessment. This study investigated the diagnostic utility of the predilection sites and clinical characteristics of MEANTs. Methods: A retrospective analysis was conducted on clinical data from 10 patients with histologically confirmed MEANTs, admitted to Eye & ENT Hospital of Fudan University between March 2016 and March 2023. Results: The median age of the patients at diagnosis was 39.3 years. Hearing loss (n = 8) and ear pain (n = 6) were the most prevalent clinical symptoms in the patients diagnosed with MEANTs. Endoscopic examination revealed diverse symptoms, predominantly presenting as non-pulsatile masses with distinct boundaries and quasi-circular shapes within the external auditory canal, often accompanied by abundant blood vessels (n = 4). Tumors were typically confined to the middle/lower tympanic chambers or eustachian tube and were frequently associated with tympanic sclerosis, particularly around the pharyngeal tube (n = 3). Pathologically, MEANTs exhibited CD56 positivity or weak positivity, along with positive staining for CKpan and Syn, negativity for S100, and Ki67 ≤3%. Personalized surgical interventions were chosen by all the patients based on lesion severity, with no subsequent radiotherapy or chemotherapy administered postoperatively. No tumor progression was noted during the postoperative follow-up. In addition, a noteworthy case was presented in which MEANT initially manifested in the middle or lower tympanic cavity and eustachian tubes. Over 2 years, the tumor progressively grew, invading the middle tympanum and surrounding ossicles, ultimately achieving complete resection with no recurrence observed during subsequent follow-up. Conclusions: A possible diagnosis of middle ear adenoma should be considered when encountering non-pulsatile tumors with clearly demarcated inner boundaries within the external auditory canal accompanied by abundant quasi-circular vessels and the presence of new bone or neoplasm at the pharyngeal tympanic canal orifice observed during preoperative examinations or surgical procedures.