Positron Emission Tomography‐Negative Mediastinal Lymph Node Metastasis From Clear Cell Renal Cell Carcinoma 11 Years After Nephrectomy Diagnosed by Endobronchial Ultrasound‐Guided Transbronchial Needle Capillary Sampling

A 73‐year‐old man was referred for evaluation of mediastinal lymphadenopathy. He had undergone right nephrectomy for clear cell renal cell carcinoma (ccRCC; pT3aN0M0, stage III) 11 years earlier and had remained recurrence‐free without adjuvant therapy. Positron emission tomography/computed tomography (PET/CT) revealed an enlarged subcarinal lymph node which was non‐FDG avid. Bronchoscopy was performed to obtain a pathological diagnosis. Endobronchial ultrasound‐guided transbronchial needle aspiration (EBUS‐TBNA) initially yielded bloody and inadequate specimens on rapid on‐site cytologic evaluation (ROSE). The sampling technique was therefore switched to endobronchial ultrasound‐guided transbronchial needle capillary sampling (EBUS‐TBNCS), and ROSE demonstrated adequate cellular material with atypical cells. Histopathology and immunohistochemistry confirmed metastatic ccRCC. This case highlights that metastatic ccRCC should be considered in PET‐negative mediastinal lymphadenopathy more than a decade after nephrectomy and that EBUS‐TBNCS may facilitate diagnostic tissue acquisition when conventional EBUS‐TBNA yields bloody specimens.