Thyroid-like Low-Grade Nasopharyngeal Papillary Adenocarcinoma: A Case Report.

INTRODUCTION:Thyroid-like low-grade nasopharyngeal papillary adenocarcinoma (TL-LGNPPA) is a rare neoplasm characterized by morphological analogy to papillary thyroid carcinoma and the abnormal expression of thyroid transcription factor-1 (TTF-1). We herein report a rare case of TL-LGNPPA with a review of its clinical and morphological characteristics and the treatment provided.PATIENT CONCERNS AND DIAGNOSIS:The patient was a 50-year-old Chinese woman with the complaint of a three-year history of phlegm with blood with pharyngeal discomfort. There were no remarkable physical findings, and the laboratory tests were normal. Laryngoscopy and nasal computed tomography identified a mass at the posterior end of the nasal septum. Histologically, the tumor exhibited an oval papillary growth. Immunohistochemically, the neoplastic cells were positive for TTF-1, vimentin, cytokeratin 7, and cytokeratin 19. Pathological examination indicated a thyroid-like low-grade nasopharyngeal papillary adenocarcinoma.INTERVENTION:The neoplasm was completely resected without any complication.OUTCOMES:The patient had neither local recurrence nor distant metastasis 1 year after the removal of the tumor.CONCLUSION:Although TL-LGNPPA is a malignant tumor, complete surgical resection is an effective treatment.