Identifying the tumor margins of skin basal cell carcinoma using multiphoton microscopy

Basal cell carcinoma (BCC) is the most common non-melanoma skin cancer, accounting for approximately 70% of global cutaneous malignancies. The initiation, progression, and dissemination of BCC are closely associated with the extracellular matrix (ECM), wherein collagen fibers, as the primary structural component, play a pivotal role in tumor advancement. Studies suggest that monitoring ECM alterations at the tumor-normal tissue interface can help elucidate mechanisms of invasion and metastasis. In this study, we employed multiphoton microscopy (MPM) to perform label-free imaging of low-recurrence-risk BCC specimens, followed by quantitative analysis of collagen fibers in the acquired images, with a focus on comparing morphological differences among the tumor margin, transition zone, and adjacent normal tissue. The results revealed statistically significant variations (P < 0.05) in collagen fiber morphology and density across these regions, demonstrating the feasibility of MPM for monitoring peritumoral collagen remodeling. This study highlights the technical advantages of MPM in BCC boundary identification and provides new insights for precise surgical margin assessment and further investigation into tumor invasion mechanisms.