Two Cases of Middle Ear Adenoma with Neuroendocrine Differentiation (Carcinoid Tumor)

Abstract

Middle ear adenoma with neuroendocrine differentiation (carcinoid tumor) is a rare benign tumor of the tympanic cavity. Carcinoid tumor is generally derived from primitive stem cells in the gut wall but can be seen in other organs, including the lungs, mediastinum, thymus, liver, pancreas, bronchus, ovaries, prostate, and kidneys. This is unusual considering neuroendocrine cells have not been identified in normal or inflamed middle ear mucosa. Carcinoid tumor of the middle ear represents a class within the spectrum of adenomatous neoplasms. Immunohistochemical techniques have helped clarify that these tumors all share elements of neuroendocrine differentiation. Although histologic and biological similarities with middle ear adenoma exist, carcinoid tumor of the middle ear should be classified as a well-differen tiated neuroendocrine carcinoma because the carcinoid tumor has higher rate of recurrence and incidence of metastasis than middle ear adenoma. Surgical management is the recommended treatment and long-term observation is necessary. � Korean J Otorhinolaryngol-Head Neck Surg 2011;54:573-7 Key WordsZZMiddle ear ㆍCarcinoid tumor.