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

ORIGINAL ARTICLE PURPOSE 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). METHODSWe 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). RESULTSMalignant 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). CONCLUSIONOur results show that there are significant differences in MSCT findings of malignant enlarged lymph nodes and benign lymph node enlargement due to anthracosis.

Dual-Energy CT–Derived Electron Density for Diagnosing Metastatic Mediastinal Lymph Nodes in Non–Small Cell Lung Cancer: Comparison With Conventional CT and FDG PET/CT Findings

“…However, size criteria alone cannot detect micrometastatic lymph node disease, as reflected by the sensitivity of only 54.5% for short-axis diameter observed in our study. Necrosis is well-recognized to be more prevalent in metastatic than in nonmetastatic nodes [29,30] and also serves as a useful diagnostic feature. Nonetheless, benign mediastinal lymph nodes, such as in the setting of tuberculosis, may exhibit necrosis…”

Benign features of infection‐related tumor‐like lesions of the lung: A retrospective imaging review study

“…We reviewed English literature for the frequencies of these eleven benign features in lung malignancy. Eight features with corresponding frequency were identified, including (i) calcification or hyperdensity (HU > 100): 14% (28), (ii) pleura‐based wedge shape: 4–25%, (iii) smooth inner wall of cavitation or doughnut sign: 2–16%, (iv) adjacent clustered small nodules: 8–9%, (v) marginal ground glass or infiltrates: 67%, (vi) central necrosis (abscess): 24%, (vii) necrosis of the lymph node: 35.2%, and (viii) strongly (>50 HU) or poorly (<15 HU) enhanced soft tissue part: 27.5% . The specific frequencies of the rest three features were not found in the literature but some descriptions of the relation with lung malignancy were noted.…”

Prediction of pathological nodal involvement by CT‐based Radiomic features of the primary tumor in patients with clinically node‐negative peripheral lung adenocarcinomas

“…Conventional CT interpretation relies on primarily size criteria to characterize lymph nodes. A short‐axis diameter bigger than 10 mm was considered as the standard threshold for abnormal nodes . However, lymph node size alone is not a reliable parameter for the evaluation of metastatic involvement in patients with NSCLC; metastases have been found in up to 20% of small nodes in patients with clinical stage cT1N0 and cT2N0 .…”