Do sonographic features of lymph nodes predict the anthracotic benign pathology in ex-coalminers with PET positive lymph nodes?

Anthracosis often presents with mediastinal lymph node enlargement. Endobronchial ultrasound (EBUS) features are useful in differentiating benign and malignant nodes, but data on anthracosis is limited. The aim of this study was to evaluate EBUS features of PET positive lymph nodes (LNs) in predicting anthracosis. We compared the EBUS features in 12 consecutive ex-miners (all males, mean age 66, mean tenure 21.9 years ) presented with PET positive (mean SUV 9.16+/-3.99) lymph node enlargement and/or pulmonary lesions. Recorded EBUS features were short axis diameter, shape, margin, echogenicity, presence of vascular patterns, septations and hyperechoic dots. Mean LN diameter was 21mm, LNs were all ovoid shaped and sampled at 7(n:4), 4R(n:2), 11L(n:2) and 11R(n:2). Homogenous echogenicity was present in 5(83%), regular margin in 6(100%), vascularity in 4(67%), hyperechoic dots in 1(17%) and septations in1(17%) anthracotic LNs(n:6), whereas homogenous hypoechoic feature was present in 3(75%), regular margins and vascularity were noted in 3(75%), 2(50%) respectively in malignant LNs(n:4) but none had septations nor hyperechoic dots. Homogenous echogenicity and regular margin were present 1(50%) nonmalignant LNs(n:2) respectively, and none had vascularity, hyperechoic dots nor septations. Mean LN size on the short axis were 27mm, 20.9mm and 16.7mm in malignant, anthracotic and nonmalignant LNs respectively. In this preliminary study, presence of hyperechoic dots were only present in anthracotic node and homogenous echogenicity, vascularity and regular margin were more prominent in anthracotic LNs, thus sonographic fetaures might be useful in predicting anthracosis.