(A842) Middle Ear Adenomatous Neuroendocrine Tumors: A Case Series Highlighting Diagnostic and Management Challenges

Introduction: Middle ear adenomatous neuroendocrine tumors (MEANTs) are exceptionally rare with scarce case reports in the English literature. These tumors have a nonspecific presentation with diagnosis relying on histopathology and immunohistochemistry. Our objective is to present the most extensive case series in the English literature that highlights clinical manifestations, diagnosis, treatment and challenges involved in MEANTs.

Methods: We present a retrospective case series of five patients with MEANTs treated at two academic tertiary institutions. Demographics, clinical presentation, imaging, histopathology, treatment, and follow-up were documented.

Results: Our cohort includes five patients (three females) aged 14 to 65 years old. The most common presenting symptoms include hearing loss, otalgia, and otorrhea. Preoperative imaging included only non-contrast temporal bone CT scan in 80% of the patients without specific findings and were suggestive of conditions such as cholesteatoma or chronic suppurative otitis media. All patients underwent tympanomastoidectomy with surgical excision. Immunohistochemistry for all specimens showed positivity for synaptophysin and chromogranin. Negative markers included S100, CD31, and thyroglobulin. Three patients experienced tumor recurrence, one after two years, one after three years and the other after 14 years, all requiring surgeries for complete excision.

Conclusions: This case series represents the largest cohort of MEANTs reported in current literature, emphasizing the diagnostic challenges posed by these tumors and the critical role of histopathology in their identification. While surgical resection is the primary treatment modality, it is challenging to achieve tumor control at the primary surgery, which highlights the need for long-term follow-up.