• congenital melanocytic nevi
• intralesional vascularization
• malignant melanoma
• UHFUS

“Intus et in cute, intus ut in cute”, Cicerone. At the entrance of the Department of Dermatology (University of Pisa, Pisa, Italy) the Cicerone’s quote introduces the patients to dermatological visit.
Congenital melanocytic nevi (CMN) are benign skin lesions, characterized from variable size from small to large that usually presents at birth. Their classification based on size is due to giant CMN having a higher risk of malignant melanoma: small < 1,5 cm, medium 1,5-19,9 cm, giant > 20 cm.
Dermoscopy and confocal laser scanning microscopy (CLSM) are the standard techniques for the diagnosis of melanoma. The prevalent dermoscopic criteria to distinguish CMN and MM are represented by atypical pigment network, atypical dots and globules, blotches, streaks, blue-grey veil, regression structure, milky red areas, multicomponent structure. Also the ABCDE clinical criteria (Asymmetry, irregular Borders, multiple Colors, Diameter > 6 mm, Evolving) may help the doctor to recognize the suspicious lesions.
However the diagnosis of malignant melanoma developed on a congenital melanocytic nevus often is complicated by the clinical and dermoscopic features of the lesion below because of its hyperpigmentation and its depth. Furthermore, also the CLSM is able to observe only superficial lesions.
Ultra-high frequency ultrasound (UHFUS) is a non-invasive technique which may find an important application in the diagnosis of MM in combination with the dermoscopy.
The objective of the study is to evaluate if the UHFUS may be helpful when the dermoscopic features of CMN are complex or not much clear. We employ Doppler ultrasound technique to acquire and compare images of MM and CMN through the intralesional vascularization’s parameter because of the absence of dermoscopic’s clear signs of malignity. Another feature analyzed is the correspondence between the ultrasonographic thickness and the Breslow thickness in melanoma using UHFUS.
We analyzed a population of 20 patients consisting of 10 CMN and 10 MM. The lesions were examined at first from a clinical and dermoscopic’s point of view searching the suspicious dermoscopic criteria of malignancy and later from an ultrasonographical ones evaluating the intralesional vascularization’s parameter.
B-mode images were obtained by using UHFUS with a 70 MHz linear probe. Color-Doppler (CD) images were used to evaluate the intralesional vascularization and the aspect of the vascular signal.
The study establishes that intralesional vascularization’s parameter represents an useful tool for the differential diagnosis of MN and MM in the preoperative diagnosis of melanoma. We obtained a vascular signal with medium-high intensity in the 100% of the MM, observing on the other hand the complete absence of medium-high strength intralesional vascularization.
Moreover, we observed a clear agreement between the ultrasonographic thickness measured with UHFUS and Breslow thickness of MM.
We conclude that ultrasonographic evaluation shows interesting data for the preoperative diagnosis of the malignant melanoma developed on the congenital melanocytic nevus through the study of the intralesional vascularization. We propose an ultrasonographic procedure in combination with the dermoscopy or the confocal microscopy, for the diagnosis of MM developed on CMN, and to select the more appropriate chirurgical approach.
The major limitation of our study is the small population in exam, therefore further studies will be needed in order to validate the ultrasonographic parameter that we proposed.