title: CT differentiation of enlarged mediastinal lymph node due to anthracosis from metastatic lymphadenopathy: a comparative study proven by endobronchial US-guided transbronchial needle aspiration.
abstract: OBJECTIVE
  Anthracosis often results in mediastinal nodal enlargement. The aim of this comparative study was to evaluate if it is possible to differentiate endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) proven anthracotic lymph nodes from malignant lymph node enlargement by means of multislice computed tomography (MSCT).
  
  
  METHODS
  We compared the MSCT findings of 89 enlarged lymph nodes due to anthracosis with 54 malignant lymph nodes (non-small cell lung cancer 75.9%, small cell lung cancer 18.5%, and non-Hodgkin lymphoma 5.6%). The lymph nodes were assessed for density (calcification, fat, and necrosis), shape (oval, round), contrast enhancement, and contour (sharp, ill-defined).
  
  
  RESULTS
  Malignant lymph nodes showed significantly greater axis diameters (P < 0.001). Both anthracotic and malignant nodes were most often oval (86.5% of all malignant nodes vs. 81.5% of all anthracotic nodes, P = 0.420) and showed confluence in a remarkable percentage (28.1% vs. 42.6%, P = 0.075). Anthracotic nodes showed calcifications more often (18% vs. 0%, P < 0.001). Malignant lymph nodes showed a significantly greater short and long axis diameter (P < 0.001), and they had a higher frequency of ill-defined contours (27.8% vs. 2.2%, P < 0.001) and contrast enhancement (27.8% vs. 5.6%, P < 0.001). Nodal necrosis, which appeared in one third of the malignant nodes, was not observed in anthracosis (35.2% vs. 0%, P < 0.001). Confluence of enlarged lymph nodes was seen in malignant lymph nodes (42.6%), as well as in lymph node enlargement due to anthracosis (28.1%, P = 0.075).
  
  
  CONCLUSIONS
  Our results show that there are significant differences in MSCT findings of malignant enlarged lymph nodes and benign lymph node enlargement due to anthracosis.
authors.affiliation: Department of Diagnostic and Interventional Radiology, Allgemeines Krankenhaus Hagen, Germany. Kirchner@akh-hagen.de.
authors.forename: Johannes
authors.initials: J
authors.lastname: Kirchner
authors.forename: Michael
authors.initials: M
authors.lastname: Broll
authors.forename: Phillip
authors.initials: P
authors.lastname: Müller
authors.forename: Natalia
authors.initials: N
authors.lastname: Pomjanski
authors.forename: Stepfan
authors.initials: S
authors.lastname: Biesterfeld
authors.forename: Dieter
authors.initials: D
authors.lastname: Liermann
authors.forename: Ralph
authors.initials: R
authors.lastname: Kickuth
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D055008:Anthracosis / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000473:pathology; D003937:Diagnosis, Differential; D061765:Endoscopic Ultrasound-Guided Fine Needle Aspiration / Q000379:methods*; D005260:Female; D006801:Humans; D008198:Lymph Nodes / Q000000981:diagnostic imaging* / Q000473:pathology*; D000072281:Lymphadenopathy / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000473:pathology; D008207:Lymphatic Metastasis; D008297:Male; D008482:Mediastinum / Q000000981:diagnostic imaging / Q000473:pathology; D008875:Middle Aged; D061330:Multidetector Computed Tomography; D014057:Tomography, X-Ray Computed / Q000379:methods