Does anthracotic pigments reported in EBUS-TBNA exclude lymph node metastasis?

Abstract

Introduction: There may be causes of mediastinal lymph node enlargement other than metastasis in cancer patients and anthracosis is one of them. Aim: The aim of this study was to evaluate if anthracotic lymph node detected by endobronchial ultrasound transbronchial needle aspiration (EBUS-TBNA) is a sign of benign conditions and excludes metastasis. Methods: Patients who underwent EBUS-TBNA for lung cancer staging or diagnosing mediastinal lymph node metastasis of ETM were included. Patients with EBUS-TBNA cytology reported as anthracotic pigments and also benign, malignancy or granulomatous inflammation were excluded. After EBUS-TBNA patients were underwent mediastinoscopy or radiological follow-up.If mediastinoscopic pathology was reported other than anthracosis or radiological follow-up showed lymph node enlargement,EBUS-TBNA was accepted as false negative. Results: Thirty one lung cancer and 19 ETM patients were included. Mediastinoscopy was performed in 23 lung cancer and 8 ETM patients. Remaing 8 lung cancer and 11 ETM patients were radiological follow-up. In lung cancer group, metastasis was reported with mediastinoscopy in 6 patients and 2 radiological follow-up patients had progression of lymph node enlargement. In ETM group only in 1 patient progression of lymph node enlargement was reported during radiological follow-up.As a result, EBUS-TBNA was false negative in 8 of 31 (25.8%) lung cancer patients and 1 of 19 (5.2%) ETM patients. Conclusion: In lung cancer patients anthracotic pigmentation of lymph nodes doesn9t exclude lymph node metastasis and mediastinoscopy should be performed before surgery. In extrathoracic malignancy patients, anthracotic pigmentation excludes metastasis.