Preoperative Assessment of Circulating Extracellular Vesicles as a Potential Biomarker for Melanoma

Background: Circulating extracellular vesicle (EV)-associated particle profiles may differ between patients with melanoma and those with benign lesions. Methods: Preoperative citrated whole blood from 77 patients with clinically suspicious lesions was assessed by direct fluorescence-based flow cytometry; histopathology identified 20 CMM cases (12 primary and 8 metastatic) and 57 benign-lesion controls. Results: The reported total particle concentration was higher in CMM than controls (3299.86 ± 456.61 vs. 2873.40 ± 427.74 events/µL). CD45+, PD-L1+, and CD45+/PD-L1+ populations were also increased. CD45+/VISTA+ particles were higher in the reduced subset of 9 CMM cases and 48 controls. Conclusions: These exploratory observations require analytical validation and independent clinical confirmation before diagnostic or prognostic utility can be established.