Thyroid-like low-grade nasopharyngeal papillary adenocarcinoma: a case report and literature review.

Abstract

Thyroid-like low-grade nasopharyngeal papillary adenocarcinoma (TL-LGNPPA) is a rare disease, and consensus regarding the diagnosis, clinical management, and prognosis for this population is lacking. This study aimed to assess the immunohistochemical features, clinical management, and prognosis of TL-LGNPPA through a comprehensive literature review. We reported a patient diagnosed with TL-LGNPPA in our institution. In addition, we reviewed the published literature from PubMed, Science Direct, Web of Science, Google Scholar, and China National Knowledge Internet to synthetically review the patient characteristics, treatments, and outcomes for TL-LGNPPA. We included 46 patients in this study, and most of them (76.1%) came from Asia. The most common symptoms were nasal obstruction, epistaxis, and bloody sputum. The tumors mainly occurred in the posterior roof of the nasopharynx or nasal septum. In patients with available immunohistochemical results, all patients were overexpression of thyroid transcription factor 1 (100%), CK7 (100%), CK19 (100%), Ckpan (100%), and epithelial membrane antigen (100%). In addition, the majority of them were Vimentin overexpression (94.7%). However, TL-LGNPPA patients were more likely to have lower-expression of CK20 (100%), smooth muscle actin (100%), Epstein-Barr virus-encoded RNA (100%), thyroglobulin (97.8%), CK5/6 (92.6%), S-100 (86.7%), and P63 (85.8%). All of the patients underwent surgery, and two of them received postoperative radiotherapy. With a median follow-up time of 16 months, and 16% of them were follow-up for more than five years, no locoregional recurrences or distant metastasizes occurred. In conclusion, TL-LGNPPA is an extremely rare entity with unique disease features and excellent prognosis. Surgery is the optimal treatment for this population.