Central intranodal blood vessel: a new EUS sign described in mediastinal lymph nodes

Abstract

The vascular architecture of normal lymph nodes is composed of prominent centrally located blood vessels. In malignant nodes, this pattern is distorted because of tumor infiltration and neovascularization. To determine whether EUS imaging of central intranodal blood vessels (CIV) can be used to differentiate benign from malignant subcarinal lymph nodes in lung cancer. CIV was defined as a > or =1-mm-diameter tubular structure, with well-defined walls and blood flow. The diagnostic accuracy of CIV was compared with other lymph-node features in a retrospective cohort of patients who underwent EUS for lung cancer evaluation. Findings were then prospectively validated in a similar cohort. Minneapolis Veterans Affairs Medical Center. Patients who underwent EUS for lung cancer diagnosis or staging at the VA Medical Center from March 2003 to March 2005. Of 67 patients included in the retrospective analysis, CIV was noted in 17 of 35 patients with benign nodes (49%), compared with 5 of 32 patients with malignant nodes (16%) (P = .002). In lymph nodes > or =1 cm, CIV was noted in 14 of 16 patients with benign nodes (88%), compared with 2 of 27 with malignant nodes (7%) (P < .001). Forty-five patients were included in the prospective validation cohort, and 16 had malignant lymph nodes. For malignant lymph-node metastasis, the absence of CIV had a sensitivity of 75%, a specificity of 97%, and an accuracy of 89%. The accuracy of CIV was superior to that of lymph-node shape; margin; and internal echo pattern, singly or in combination. The absence of a central intranodal blood vessel was a strong and independent predictor of malignancy in lymph nodes of patients with lung cancer and can be used to select lymph nodes for FNA.