Efficacy of endoscopic resection and intensity-modulated radiotherapy for thyroid-like low-grade nasopharyngeal papillary adenocarcinoma: a case report

BACKGROUND: Among the malignant tumors that occur in the nasopharynx, nasopharyngeal carcinoma is the most common. Nasopharyngeal carcinoma (NPC) is commonly diagnosed in Southeastern Asia, particularly in southern China. It originates from the epithelial lining of the nasopharynx and has a variety of pathological subtypes. The vast majority of NPC cases are keratinizing or nonkeratinizing squamous cell carcinoma. Low-grade nasopharyngeal papillary adenocarcinoma (LGNPPA) is an extremely rare malignant tumor. Most reports regarding this disease mainly focus on clinical diagnosis and pathology; however, reports regarding therapy and follow-up are relatively limited. The case in the study presents a female patient with LGNPPA. The patient underwent endoscopic resection and adjuvant radiotherapy. Following-up 6 years, the patient was free of local recurrence and distant metastasis. Because of the very low incidence, there are no guidelines or protocols developed for proper, standardized therapy, we aim to provide useful recommendations regarding optimal treatment strategies by exploring the therapeutic expectancies of the rare disease. CASE DESCRIPTION: A 45-year-old female of Han ethnicity visited a local hospital for over 2 years of recurrent nasal congestion. The patient had no previous medical history, had a history of smoking (6 years, 20 cigarettes per day) and drank occasionally. but had no family history of cancer. Epstein-Barr virus (EBV) DNA was <500×10(2) IU/mL. Based on findings from computed tomography (CT) scans of the nasal cavity and paranasal sinuses, nasal endoscopy, and postoperative pathology, the diagnosis was low-grade papillary adenocarcinoma located at the upper nasopharynx (T1N0M0, stage I). This patient underwent endoscopic resection. After the endoscopic resection, she received intensity-modulated radiotherapy. After radiotherapy, there was no residual by nasopharyngo-fiberoscope. And she was free of local recurrence and distant metastasis at 6 years of follow-up. CONCLUSIONS: Although primary nasopharyngeal adenocarcinomas (NPACs) are very rare, they also should be pay attention to. As far as treatment policy, no standard treatment exists for the tumors. So through this case report, we want to provide a possible useful recommendations regarding optimal treatment strategies by exploring the therapeutic expectations of this rare disease.