Sonographic appearances of cervical lymph nodes: Variations by age and sex

Purpose. The purpose of this study was to evaluate the age- and sex-related variations in the numbers and sonographic appearances of normal cervical lymph nodes. Methods. One hundred thirty-three healthy subjects (67 men and 66 women) underwent sonographic examinations of the neck, during which 1, 299 lymph nodes were detected. The lymph nodes were assessed for their size, shape (short-to-long-axis ratio), and border sharpness, as well as for the presence of an echogenic hilum. The subjects were categorized by age (20-29, 30-39, 40-49, and ≥ 50 years) and subcategorized by sex. The differences between the groups in the number of nodes and in their appearance were evaluated. Results. The mean number of nodes visualized on sonography was significantly higher (p < 0.05) in subjects aged 20-29 and 30-39 years than in subjects aged 40-49 and 50 years or older. The difference in the mean sizes of the cervical nodes between men and women was not statistically significant. The lymph nodes in subjects aged 20-29 and 30-39 years were commonly smaller than those in subjects aged 40-49 and 50 years or older, but the differences were not statistically significant. Neither the shape nor the border sharpness of the cervical lymph nodes varied significantly by age or sex. The incidence of an echogenic hilum within the lymph nodes increased significantly with age in both sexes (p < 0.05). Conclusions. This study provides information about the sonographic appearances of and variations between normal cervical lymph nodes. The presence of an increased number of cervical lymph nodes and the absence of an echogenic hilum within the nodes may help to identify an abnormality more in older patients than in younger patients.