The purpose of this study was to evaluate short- and long-axis diameters of enlarged cervical lymph nodes with ultrasonography and to determine whether the long-to-short axis (l/s) ratio is a valid diagnostic parameter in the differentiation between benign and malignant nodal disease. 730 enlarged cervical lymph nodes in 285 patients were examined with ultrasound. The short- and the long-axis diameters of each enlarged node were measured and the l/s ratio calculated. Definite diagnoses of the nodes were obtained by histological examination following neck dissection. 95% of enlarged cervical nodes shown on ultrasound to have a l/s ratio of more than 2 were correctly diagnosed as benign. Nodes presenting with a more circular shape and a l/s ratio of less than 2 were diagnosed correctly as metastases with 95% accuracy. The l/s ratio of lymph nodes thus provides an excellent criterion for differentiation between benign and malignant enlargement in cervical lymphadenopathy.

In this prospective study 45 patients with cervical lymphadenopathy treated by operation, radiation and/or chemotherapy were examined by color-duplex sonography. The aim was to investigate the lymph node perfusion and to find out whether differentiation between benign and malignant nodal disease after therapy was possible by resistance and pulsatility indices. In 200 of 245 lymph nodes (82%) color-duplex sonography was able to detect perfusion. Using a pulsatility index (PI) threshold of 1.6 and resistance index (RI) threshold of 0.8, differentiation between reactive nodal enlargement and metastases was possible with an accuracy of 96%. Differentiation between lymphomas and metastases by RI and PI was not possible. Qualitative assessment of perfusional patterns was useful in detecting malignancy because reactively enlarged nodes showed greater hilar perfusion whereas metastases showed an increased peripheral perfusion. Lymphomas had both increased central and peripheral perfusions.