EUS-FNA for Retropharyngeal Lymph Node (RPLN) in Recurrent Nasopharyngeal Carcinoma (NPC) Patients

Inclusion Criteria: 1. had undifferentiated, non-keratinizing carcinoma at the initial diagnosis (WHO, 1991 criteria) and no evidence of distant metastasis obtained before radiotherapy; 2. received regular chemotherapy with cytotoxic agents such as cisplatin, carboplatin, 5-fluorouracil, paclitaxel, etc, and coordinated with radiotherapy with standard doses (approximate 50-70 Gy) in nasopharynx and neck respectively. Within 3 months after radiotherapy, no local and distant lesions were found; 3. during regular follow-up , the enlarged RPLN was detected by MRI more than 6 months later since radiotherapy accomplished; 4. didn't receive chemotherapy radiotherapy, immunotherapy or salvage surgery from completion of radiotherapy to suspicious recurrent lesion in RPLN detected; 5. no recurrent lesion in nasopharynx was found by white light endoscopy as well as cancer cell negative in pathology by bite biopsy; 6. single lesion in RPLN, and no other recurrent or metastatic lesion was found in local region or distant organ. 7. the minimum axial diameter of RPLN was more than 5mm. Exclusion Criteria: * (1) patients with nasal stenosis; (2) patients with coagulation dysfunction; (3) patients with distant metastasis