Vascularization of reactively enlarged lymph nodes analyzed by color duplex sonography.

PURPOSE

This study involved a prospective evaluation of the reliability of sonography, and especially duplex sonography, in confirmation of the benign nature of enlarged cervical lymph nodes.

PATIENTS AND METHODS

In 53 untreated patients with enlarged cervical lymph nodes, B-mode, plain, and d-galactose-enhanced color duplex sonography were performed. The B-mode sonomorphology was analyzed for the structure of vascularization. Quantitative parameters such as maximum flow velocity, pulsatility index, and resistive index were also assessed. The benignity of the lymph nodes was confirmed by microscopic analysis.

RESULTS

The B-mode showed 20 homogeneous lymph nodes, 23 with a central echogenoic line covering less than one third, and 10 with a distinct hilus sign extending to more than one third of the lymph node diameter. Microscopically, the least fibrotic or chronic inflammatory changes in the parenchyma were observed in the homogeneous lymph nodes, whereas those with central echogeneoity had fibrotic and lipoid hilus changes. Histologically, all lymph nodes had normal afferent and efferent hilus vessels. In 37 lymph nodes, the vessel structure could be reliably visualized by both plain and enhanced color duplex sonography, whereas in 16 it could only be demonstrated after the use of signal enhancement. Nine of 53 lymph nodes had Solbiati-(L/T-) indices below 2, which were suggestive of malignancy. Quantitative flow parameters did not provide useful information.

CONCLUSION

Color duplex analysis of enlarged lymph nodes is a useful method for assessment of benignity, especially after application of a signal-enhancing agent.