Vol. 101 No. 7 July 2008
A Case Report of an Oncocytoma Occurring
in the Lacrimal Sac
Masaki Kawabata, Tatsuya Fukuiwa and Yuichi Kurono
An 82-year-old man was referred to our hospital with bloody rhinorrhea on the right side of 3 months' duration. There was no history of bloody tears, nasal pain and nasal obstruction. On physical examination, a mobile and elastic soft mass was slightly palpable in the area of the right lacrimal sac. Nasal endoscopic examination revealed a soft reddish mass located in the right inferior nasal meatus. CT scan showed an enhanced soft tissue mass filling the right nasolacrimal duct from the orbit to the nasal cavity. There was no bone destruction. MRI showed a low-intensity mass on T1-weighted images and a high-intensity mass on T2-weighted images. The tumor was enhanced by gadolinium. A biopsy was performed from the tumor in the inferior nasal meatus. On histology, the tumor consisted of large cells with abundant granular cytoplasm and an oval nucleus, which formed a solid and occasionally trabecular pattern. These findings were interpreted as suspected acinic cell carcinoma. The tumor was excised en bloc by a right medial maxillectomy with lateral rhinotomy, removing the medial wall of the maxillary sinus and the medial part of the orbit. The resectioned dark-brown tumor was 40×10×8 mm and possessed a well-defined capsule. Histrologically, the tumor was composed of large cells with abundant eosinophilic granular cytoplasm and an oval nucleus, which formed a solid and occasionally trabecular pattern. Neither nuclear atypia nor mitosis was found. Immunohistochemically, tumor cells were positive for antimitochondrial antibody, cytokeratin (AE1/AE3). The Ki-67 labeling index was ＜1％. Taken together, the tumor was diagnosed as oncocytoma. He remained disease free at 13 months' follow-up.
Key words :oncocytoma, lacrimal sac, nasolacrimal duct
第101巻7号 目次 Vol.101 No.7 contents