Ultrasound examination of regional lymph nodes significantly improves early detection of locoregional metastases during the follow-up of patients with cutaneous melanoma: results of a prospective study of 1288 patients

Abstract

Background: In regional lymph node metastasis of cutaneous melanoma, the number and volume of involved lymph nodes are the most important prognostic factors. Several studies have revealed that palpation of the lymphatic drainage area(s) and regional lymph nodes has a high rate of false-negative results during follow-up. The aim of the current study was to assess the sensitivity and specificity of ultrasound versus clinical diagnosis in the detection of subcutaneous and regional metastases.

Methods: During a period of 42 months, a total of 6328 lymphatic drainage areas were examined clinically and by ultrasound (7.5-10 MHz) in 1288 melanoma patients at 4435 follow-up consultations. When an ultrasound finding was suggestive of metastasis, surgery and histopathologic evaluation were performed. The results of clinical examination, ultrasound examination, and histopathologic findings were compared.

Results: In 504 ultrasound examinations performed on 235 patients, metastatic disease was diagnosed in 263 examinations following surgery (179 patients). Due to advanced disease or rejection, an additional 56 patients did not undergo surgery. In 239 of the 263 positive findings (90.9%), metastases from melanoma were histopathologically confirmed. In 8 cases (3%) a second malignancy and in 16 cases (6. 1%) benign lymphadenopathy was histopathologically diagnosed. Palpation of subcutaneous lymph nodes and lymph nodes gave false-negative results in 68 of the 238 cases of histopathologically proven metastases (28.6%). Clinical examination was least sensitive in the supraclavicular, axillary, and infraclavicular regions. The sensitivity and specificity for ultrasound examination were 89.2% and 99.7%, respectively, and 71.4% and 99.7% for clinical examination, respectively.

Conclusions: For early diagnosis of in-transit and regional lymph node metastases in cutaneous melanoma, ultrasound scanning is distinctly superior to clinical examination. Controlled follow-up studies are proposed to examine the possible beneficial effects on survival time resulting from the ultrasound examinations of the lymphatic drainage area(s) and regional lymph nodes.