Endoscopic Ultrasonography-guided Fine Needle Aspiration for Computed Tomography-negative and Positron Emission Tomography-positive Mediastinal Lymph Node in a Patient with Recurrent Lung Cancer.

Biopsy is required to confirm lymph node (LN) metastasis in position emission tomography (PET)-positive LN due to the low specificity of PET. Currently, invasive surgical techniques such as mediastinoscopy or mediastinotomy are standard procedures for obtaining LN specimen. It would be desirable to have a less invasive way of sampling suspicious LN. Herein, we report a case of successful endoscopic ultrasonography-guided fine needle aspiration (EUS-FNA) for the diagnosis of CT-negative and PET-positive LN that was found after curative resection in lung cancer. To the best of our knowledge, this is the first description in Korea to perform EUS-FNA for the evaluation of metastatic LN during the follow-up period after lung cancer resection.A 63-years old male patient was diagnosed as a stage T4N0M0 non-small lung cancer. VATS-aided left upper lobectomy with mediastinal LN dissection was performed, and the patient revealed no recurrence for a year. During the follow up, serum level of CEA increased to 7.8 ng/mL, but CT failed to show any suspicious lesions. On PET-CT finding, a hypermetabolic lesion was noted in paraesophageal LN. We performed EUS-guided FNA to obtain a biopsy specimen from paraesophageal lymph node, and this proved to be a metastatic adenocarcinoma. In conclusion, EUS-FNA provided minimally invasive confirmation of the metastatic LN in recurrent a lung cancer patient after curative resection. EUS-FNA should be considered for suspicious metastatic LN to confirm malignancy.