An Eustachian Tube Neuroendocrine Carcinoma: A Previously Undescribed Entity and Review of the Literature.

Primary sinonasal and middle ear neuroendocrine carcinomas are rare malignancies of the head and neck. Owing to the rarity of these tumors, the clinical behavior and optimal management of these tumors are not well defined. We present a case of an incidentally discovered sinonasal neuroendocrine carcinoma that was found to originate from the Eustachian tube, which has not previously been described in the literature. This patient was treated with primary surgical resection using a combination of transnasal and transaural approaches and achieved an incomplete resection. Follow-up imaging demonstrated continued tumor growth in the Eustachian tube as well as a new growth in the ipsilateral cerebellopontine angle and findings suspicious of perineural invasion. However, the tumor exhibited a benign growth pattern and despite continued growth the patient did not receive additional treatment and he remains asymptomatic 35 months following his original surgery.