[Value of high frequency (20mhZ) and doppler ultrasound in the diagnosis of pigmented cutaneous tumors].

Purpose: Diagnosis of pigmented skin tumors is often difficult. The aim of the present study is to evaluate high frequency ultrasound and Doppler ultrasound in the localization and the characterization of these tumors.
Material and Methods: One hundred and seventy six pigmented skin tumors including melanocytic and non melanocytic, benign and malignant lesions have been examined before resection using high frequency ultrasound (20MHz probe) and Doppler ultrasound (13MHz probe-Doppler frequency: 7MHz). Imaging data have been correlated with histological data, available in all cases.
Results: Tumors seen at ultrasound were hypoechoic lesions, some of which, particularly malignant melanocytic tumors were vascularized. Precise ultrasonographic location of the tumor was correlated to its histological location: epidermis for purely epidermal proliferations (seborrheic keratoses), superficial dermis for dermal proliferations originating from epidermis (benign dermal nevi, melanomas during vertical growth phase, basal cell carcinomas), middle and deep dermis for dermal proliferations originating from dermis (fibrous histiocytomas, angiomas).
Conclusion: Ultrasound may help in assessing positive and differential diagnosis of pigmented skin tumors as it precises, before histological examination, the exact location of the lesion within the different skin layers and its origin. As far as malignant melanocytic tumors are concerned, high frequency ultrasound and Doppler ultrasound appear promising in diagnosis algorithm and pronosic of these lesions.