Exclusive Endoscopic Resection of Nasopharyngeal Papillary Adenocarcinoma via Combined Transnasal and Transoral Approach
An otherwise healthy 31-year-old female visited with complaints of nasal obstruction and mild postnasal drip for several weeks. Transnasal and transoral nasopharyngoscopic evaluations disclosed a tumor almost completely occluding nasopharynx (). The mass was exophytic, irregularly-surfaced, and very fragile even to endoscope-guided careful palpation and suction. Small tumor fragment was unintentionally dislodged during office-based endoscopic examination. Subsequent surface bleeding was only scanty without any problems, which suggested hypovascular feature of this tumor. Detailed examination of tumor attachment area and adjacent invasion was difficult in the office due to the excessive intracavitary bulging. Dislodged tumor dislodged piece of the tumor was sent for pathologic examination, which revealed the presence of LGNPPA. Computed tomography showed a 2.8×2.4 cm-sized, relatively hypovascular tumor without deep invasion or cervical lymphatic metastasis. The tumor exhibited typically exophytic feature. Through serial images, the point of stalk was estimated to be the narrow area around the cranial end of the nasal septum and the nasopharyngeal vault (). An 18-fluorodeoxyglucose positron emission tomography/computed tomography scan showed a mildly increased standardized uptake value of 2.55 without uptake elsewhere (). Thyroid ultrasonography revealed no thyroid nodule, especially no suspicious signs suggesting malignancy. Free T4, thyroid stimulating hormone, and thyroglobulin were all within the normal range.\nOperative exploration under general anesthesia was planned both for evaluation and curative resection. Endoscopic exploration via combined transnasal and transoral approach was tried first, under preparation of further transpalatal or transfacial approach. At first, inferior and middle turbinates of both sides were lateralized or partially resected for visualization. The tumor, protruded into the choana of both nasal cavities, was carefully probed and mobilized. Area of tumor attachment was the narrow area in the nasal septum around choana and nasopharyngeal vault. Considering the tumor attachment confined only in narrow portion, we then decided to try exclusive endoscopic resection without transfacial or transpalatal approach. We tried to keep the resection margin to 0.5 cm around the tumor. Although en-bloc resection was originally planned, tumor was partially dislodged due to its fragility during the manipulation. But subsequent wider surgical field made the endoscopic resection more feasible. Mucosal incision was then made in the region around tumor stalk with sickle knife. Tissue was elevated from the underlying bony structure. This revealed no identifiable deep invasion and dissections were performed easily. Eventually, the mass and surrounding mucosa was successfully separated from the nasopharyngeal vault, and delivered transorally due to its large size.\nThe gross texture of the tumor was gritty, and fragile. The tumor was confined only to the shallow submucosal layer without deeper invasion. Although it was not encapsulated, resection margins were clear. It exhibited papillary growth pattern of glandular epithelial cells (). A thin fibrovascular core was visible without calcified psammoma bodies. The cells lining these structures had bland, round-to-oval, nuclei without mitotic figures (). Immunohistochemistry disclosed positivity for thyroid transcription factor-1 (TTF-1) () and cytokeratin 7 (CK7), but negativity for thyroglobulin () and CK20. These findings were considered identical to the previously described characteristics of LGNPPA []. The patient was kept in hospital overnight and the posterior packing was removed the next day without any complications or morbidities. She did not receive adjuvant radiation therapy or chemotherapy. At 3 years after surgery, she remains free of disease ().