Primary Nasopharyngeal Papillary Adenocarcinoma: Report of 2 Cases and Review of the Literature.

The primary nasopharyngeal papillary adenocarcinoma (NPPA) is extremely rare which accounts for less than 0.48% of all malignant neoplasms in the nasopharynx. The clinical features, diagnosis, and treatment of NPPA have not been well described. We present 2 patients with NPPA that were treated with total endoscopic resection and radiotherapy at Vietnam National Cancer Hospital. Through these cases and reviewing of the literature, we provide deeper understanding of NPPA to highlight clinical pathological characteristics and the optimal treatment strategy for patients with pathologically confirmed NPPA. Our 2 cases were successfully treated and remained disease-free 4 years after treatment. The NPPA was usually an indolent tumor with polypoid appearance and slow growth rate and has a good prognosis. Surgical excision, including endonasal endoscopic excision with or without adjuvant radiotherapy, was most effective with a localized and operable tumor.