BACKGROUND:Ultrasonography with fine-needle aspiration cytology (FNAC) has proven to be a valuable diagnostic tool in the preoperative workup of patients with breast cancer or penile cancer eligible for sentinel lymph node biopsy. The aim of this study was to evaluate the use of this technique in the initial assessment of patients with primary cutaneous melanoma. METHODS:A total of 107 patients with cutaneous melanoma eligible for sentinel node biopsy with clinically negative nodes were studied prospectively. Patients underwent ultrasonography of potentially involved basins and FNAC in case of a suspicious lymph node. The sentinel node procedure was omitted in patients with tumour-positive lymph nodes in lieu of lymph node dissection. RESULTS:Ultrasonography with FNAC correctly identified disease preoperatively in two of the 107 patients (2%). Thirteen of the 22 patients (59%) with a suspicious node on ultrasonographic imaging but a tumour-negative fine-needle aspirate were shown to have involved nodes. Of the 85 patients with ultrasonographically normal nodes, 25 (29%) were shown to have metastases. Of the total of 43 involved basins, 16 contained metastases > 2 mm and 25 < or = 2 mm. CONCLUSIONS:In our hands, the sensitivity and specificity of preoperative ultrasonography to detect lymph node involvement in patients with melanoma are 34% and 87%, respectively. In combination with FNAC, this is 4.7% and 100%, respectively. This yield is insufficient for this technique to be used as a routine diagnostic tool in the selection of patients eligible for sentinel node biopsy.