Lymph node sonography versus palpation for detecting recurrent disease in patients with malignant melanoma

The aim of this study was to examine the efficacy of lymph node palpation versus high resolution lymph node sonography for the detection of lymph node metastases in patients with malignant melanoma. We retrospectively evaluated 2256 pairwise lymph node examinations of the cervical, axillary and inguinal region by palpation and sonography in 264 patients with resected melanomas greater than 0.75 mm of invasion thickness. Lymph node metastases occurred in 50 patients (19%) which were detected in 38 (76%) by both methods in agreement. In 7 cases (14%) palpation failed, in 3 cases (6%) sonography failed and in 2 cases both methods failed to identify metastases. The overall sensitivity of detecting metastatic disease was 82% for palpation and 90% for sonography which was statistically not different. The overall specificity by sonography (99%) was significantly better than for lymph node palpation (88%). Taking into account the results of this analysis, we conclude that patients with a negative result by lymph node palpation do not need further sonography for verification. However, any suspect result by palpation should be additionally evaluated by lymph node sonography in order to rule in or out metastatic disease.