Ultrasound imaging features of cervical lymph nodes with melanoma metastasis compared with benign cervical nodes

Cutaneous melanoma is the most lethal form of skin cancer, accounting for a small fraction of global cancers but a disproportionate share of skin cancer deaths. Accurate detection of lymph node involvement is critical, as nodal metastasis reduces long-term survival in patients with melanoma. This study aimed to highlight the diagnostic accuracy of ultrasound in distinguishing cervical lymph nodes with melanoma metastasis from benign cervical lymph nodes. A retrospective review of 115 cervical lymph nodes from 87 patients who underwent fine needle aspiration biopsy for suspected melanoma metastasis was conducted. Sonographic images were independently assessed by two neuroradiologists for nodal margin, cortical echogenicity, hilum, vascular flow pattern, posterior acoustic enhancement, cystic change, calcification, and anteroposterior (AP) and transverse diameters. Of 115 nodes, 48 were metastatic, and 67 were benign. Cervical lymph nodes with melanoma metastasis more frequently exhibited irregular margins (P < 0.001), hypoechoic cortex (P = 0.02), obscured or absent hilum (P = 0.001), abnormal vascular flow (P < 0.001), posterior acoustic enhancement (P < 0.001), larger AP diameter (P < 0.001), and larger transverse diameter (P < 0.001) than benign nodes. Multivariate logistic regression incorporating age and sex into the model identified irregular margins [adjusted risk ratio (aRR) = 1.79, odds ratio (OR) = 7.63, P = 0.02], absent or disorganized vascular flow (aRR = 1.82, OR = 5.05, P = 0.01), and posterior acoustic enhancement (aRR = 1.90, OR = 6.61, P < 0.001) as independent predictors of malignancy.