Background: Polarized dermoscopy (PD) is the established non-contact imaging modality for basal cell carcinoma (BCC). Cross-polarized macro photography (CPMP) applies analogous optical principles using widely available equipment, but its performance relative to PD has not been systematically evaluated. Objective: To compare dermoscopic feature visibility, image quality, and expert modality preference between CPMP and PD in BCC using a blinded, paired-image design. Methods: One hundred paired CPMP and PD images of histopathologically confirmed BCCs, acquired during the same clinical visit, were digitally masked to remove modality-revealing cues and reviewed in randomized side-by-side pairs. Feature visibility was assessed by three dermoscopists; image quality by a multidisciplinary panel using the DIQS-5 (a structured 5-point dermoscopic image quality scale); and modality preference by three dermatologists with varying CPMP familiarity across two blinded rounds with a washout period. Results: Feature visibility did not differ significantly for any established BCC criterion (all P > 0.05). CPMP scored significantly higher for depth of field and color fidelity (both P < 0.001); sharpness was comparable between modalities (P = 0.494). CPMP captured all lesions ≥ 1 cm in a single frame, whereas 41.5% of large lesions exceeded PD’s field of view. The majority of raters preferred CPMP in both evaluation rounds, with phenotype-dependent patterns: CPMP was favored for pigment-rich lesions and PD for lesions with fine vascular structures. Conclusion: CPMP demonstrated feature visibility comparable to PD while offering measurable advantages in depth of field, field of view, and color rendering, suggesting complementary roles for these modalities in BCC imaging. Plain Language Summary: Basal cell carcinoma is the most common skin cancer. Dermatologists usually examine these lesions with a handheld device called a dermoscope, which uses a special polarized light to reveal details beneath the skin surface. Standard dermoscopes work best when held close to the skin and cover a small area at a time, which can be challenging with larger growths. We wanted to know whether a photographic technique called cross-polarized macro photography (which uses the same type of light but works at a distance with a regular camera) could show the same information. We studied 100 people diagnosed with basal cell carcinoma. For each person, we had two images of the same skin area: one taken with the camera technique and one with a dermoscope. Different skin specialists reviewed the paired images side by side, without knowing which technique produced each image. They recorded what they could see, scored the image quality, and chose which image they found more useful. We found that both techniques showed the important visual features of basal cell carcinoma equally well. The camera technique produced sharper focus across the whole lesion, more accurate colors, and a wider view, often capturing larger growths in a single image. Dermoscopy showed fine blood vessels slightly more clearly. These results suggest that cross-polarized macro photography can work alongside dermoscopy in everyday practice. Each technique has its own strengths, and together they may give clinicians a more complete picture when examining skin lesions. Left side shows two labelled device setups. Upper left setup labels: DSLR Camera above a Macro lens; below the lens a Ring flash and CP filter; below, a labelled Basal cell carcinoma cross section. Legend labels: Polarized light, Depolarized light, Blocked light. Lower left setup labels: Polarized dermoscope above a labelled Basal cell carcinoma cross section, with the same legend labels. Center shows two large labelled arrows: “ 100 paired images of BCC lesions” followed by “Anonymized, randomized, blinded evaluation.” Right side shows four clinical photographs arranged as two at the top and two at the bottom. Right text lists labels under CPMP: Better depth of field; Better color fidelity; Wider field of view. Right text lists labels under PD: Finer vascular detail; Similar visibility of key BCC features.Labelled diagram comparing Cross-polarized Macro Photography and Non-contact Polarized Dermoscopy for Basal cell carcinoma. Keywords: dermoscopic feature visibility, image quality, medical photography, non-contact imaging, skin cancer imaging, optical imaging
Erdem et al. (Wed,) studied this question.