Lymph node ultrasound uses high-frequency imaging to assess cervical, axillary, inguinal, and other superficial lymph node groups for features suggesting reactive enlargement versus malignancy. It plays a key role in cancer staging, post-treatment surveillance, and guidance of lymph node biopsy.
Normal lymph nodes are oval with a central echogenic fatty hilum. Sonographic features raising concern for malignancy include round shape, absent hilum, heterogeneous cortex, cortical thickening greater than 3 mm, and internal necrosis or calcification. Doppler assessment showing peripheral or chaotic vascularity may further support malignant involvement. Ultrasound-guided core needle or fine-needle biopsy provides tissue for histopathologic diagnosis.
Lymph node ultrasound is performed as part of small parts scanning (RDMS SP credential) and is particularly relevant in oncology imaging programs, head and neck surgery, breast oncology, and melanoma surveillance. Sonographers collaborate closely with oncologists and surgeons to guide staging decisions and biopsy planning. Familiarity with lymph node drainage patterns for specific malignancies enhances the diagnostic value of the examination.