High-frequency ultrasound in the diagnosis of selected non-melanoma skin nodular lesions

Introduction
Ultrasonographic examination is commonly used in an outpatient setting, possibly due to its low cost, low risk for patients and the possibility to obtain real time images. Typically used heads have the frequency ranging from 7.5 to 12 MHz. Higher frequencies ensure higher resolution, yet they are limited by the penetration depth – reaching from several to several tens of millimetres into the skin. High-frequency ultrasonography (HFUS) appears to be a promising method for the detection and differential diagnostics of selected nodular skin lesions.

Aim
The study aimed at a comparison of the data obtained by using HFUS, histopathological and dermatoscopic images of selected skin lesions to determine their common features.

Material and methods
Nodular lesions classified as potentially malignant were subjected to clinical, dermatoscopic and high-frequency ultrasonographic examinations. Then the patients were referred for surgical removal with histopathological assessment.

Results
A total of 54 nodular lesions were examined, out of which 34 were diagnosed as non-melanoma. The most common lesions were melanocytic naevi dermatofibroma, nodular basal cell carcinoma and pyogenic granuloma. Other examined lesions included blue naevus, seborrheic wart, xanthogranuloma juvenile and Spits naevus. In all lesions except Spitz naevus, HFUS images corresponded at least with dermatoscopic or histopathology images.

Conclusions
HFUS can be used as a supporting diagnostic tool ensuring better pre-operative proceedings. HFUS is a non-invasive, easy and inexpensive screening method for the determination of different skin cancers as it provides valuable information allowing to determine the cutting margins and lesion shape.