Purpose: We investigated the predictive capabilities of high frequency, high resolution ultrasound (US) in the preoperative assessment of tumor thickness in cutaneous malignant melanomas. This evaluation is a valuable help for correct surgical planning.
Material and methods: December 1997 to August 1998, we studied with US over 120 pigmented skin lesions and collected the data, including the final histologic diagnosis, of 78 of them, which make our series. Sixty-six of 78 lesions were histologically defined as cutaneous malignant melanomas with superficial spread and the other 12 as melanocytic nevi. All examinations were carried out with an Esaotebiomedica AU 5 Harmonic scanner equipped with a 20-MHz annular array probe and a linear 13-MHz probe; B-mode, color and power Doppler images were always acquired.
Results: The statistical analysis of the comparative US and histologic measurements of tumor thickness showed very good agreement, with a high Pearson's coefficient (R: .93). However, US frequently underestimated the actual thickness relative to histology, which is in contradiction with previous literature reports. We could study with US the melanoma in situ, which has never been described before. Last but not least, low-thickness melanomas had very few color and power Doppler signals.
Conclusions: US is the correct tool for the preoperative assessment of the thickness of cutaneous malignant melanomas because it provides high agreement with histologic data even in lesions thinner than 1 mm.