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

Abstract

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.

Keywords: carcinoid tumor; cytodiagnosis; fine needle aspiration cytology; middle ear.

Figure 1.

Endoscopic results of the left ear. Subcutaneous smooth tumor protruding into the external acoustic meatus without pulsating. The tympanic membrane was not identified.

Figure 2.

Axial magnetic resonance imaging of the temporal bone. The tumor lesion was primarily present in the tympanic cavity and extended to the mastoid antrum and mastoid cells. (A) Gadolinium enhanced T1-weighted imaging depicting tumor (arrow) with low contrast enhancement, excluding the possibility of vascular lesions, such as glomus tumors. (B) Diffusion-weighted imaging depicting low intensity tumor lesion (arrow), excluding the diagnosis of cholesteatoma.

Figure 3.

Cytological results. (A) Cytological results revealing that the tumor was composed of small uniform cells with small round nuclei and granular eosinophlic cytoplasm, arranged in a nested pattern. (B and C) Tumor cells were positive for (B) synaptophysin and (C) cytokeratin CAM5.2 immunocytochemically.

Figure 4.

Pathological findings. (A) The tumor was histologically composed of small uniform cells with small round nuclei and granular eosinophilic cytoplasm, and was proliferating in trabecular and mosaic patterns (hematoxylin and eosin stain). (B) Immunohistochemical studies revealed positive for synaptophysin.