Significance of cytodiagnosis in primary carcinoid tumor of the middle ear: A case report

: Primary carcinoid tumors of the middle ear are uncommon. Cytodiagnosis of the middle ear is not usually performed as a preoperative examination because of the anatomical structure of the middle ear. To the best of our knowledge, the present study reports for the first time a case of a carcinoid tumor of the middle ear, which was preoperatively diagnosed using cytodiagnosis, and also review current literature. A 22-year-old woman complained of left-sided otalgia. A subcutaneous tumor in the left middle ear was observed. Magnetic resonance imaging revealed that the tumor was primarily present in the tympanic cavity of the middle ear and extended to the mastoid antrum and mastoid cells of the middle ear and to the external acoustic meatus. Fine needle aspiration cytology was performed from the tumor protruding into the external acoustic meatus. Cytologically, the tumor was composed of small uniform cells with small round nuclei and granular eosinophilic cytoplasm, arranged in a nested pattern. Tumor cells were immunocytochemically positive for synaptophysin and cytokeratin CAM5.2. These results indicated that this was a neuroendocrine tumor. No other tumor lesions were identified on computed tomography scans, and the tumor was considered to be the primary lesion. Tympanoplasty and mastidectomy were then performed and carcinoid tumor was diagnosed in the postoperative pathological diagnosis. To the best of our knowledge, the present study is the first to report on preoperative cytodiagnosis for carcinoid tumors of the middle ear.