Primary Olfactory Neuroblastoma of the Nasopharynx: A Case Report.

Olfactory neuroblastoma (ONB) is an ectodermal malignant tumor originating from the olfactory nerve epithelium of the nasal cavity and paranasal sinus. Olfactory neuroblastoma is a rare cancer, with an estimated incidence of 0.4 per million. Olfactory neuroblastoma often occurs in the top of the nasal cavity or near the lateral wall of the middle turbinate, which accounts for approximately 3% to 5% of the nasal cavity and paranasal sinus tumors. Olfactory neuroblastoma primarily in the nasopharynx is rare and tends to be misdiagnosed as nasopharyngeal carcinoma. Herein, we presented a case of ONB of the nasopharynx with recurrent nasopharyngeal tumor and by lymph node metastasis in both sides of the neck 14 months after surgical removal of the primary ONB. Long-term disease-free survival was achieved by definitive radiotherapy. Surgery combined with radiotherapy or definitive radiotherapy is recommended for primary ONB of the nasopharynx, radiotherapy target delineation including nasopharynx and pharyngeal lymph nodes, and neck lymph node drainage area of level Ib, Ⅱ, and Ⅲ.