Epiluminescence

Epiluminescence refers to a noninvasive technique used in dermatology for the examination of pigmented skin lesions. Also known as epiluminescence microscopy or dermoscopy, it relies on illuminating the lesion through a transparent contact plate with a liquid interface to reduce surface reflections and reveal subsurface structures. Light can be used in polarized or non-polarized form; non-polarized dermoscopy employs immersion fluids to minimize glare at the skin surface, while polarized dermoscopy uses cross-polarized light to reduce surface reflections and sometimes allows deeper visualization.

During examination, the clinician looks for characteristic patterns in the pigmented network, including pigment network, pseudopodia-like streaks, multiple globules, dots, regression structures, and, in melanoma, the blue-white veil. The technique improves the diagnostic accuracy for distinguishing malignant melanoma from benign nevi and other lesions, and is widely used as an adjunct to clinical assessment and dermato-pathology. It does not replace biopsy; lesions with suspicious patterns are biopsied for histopathological confirmation.

History: The method originated in the 20th century as a noninvasive adjunct to clinical evaluation of pigmented lesions. The term epiluminescence reflects the visualization of pigmented structures under specialized illumination; today the broader term dermoscopy is more commonly used.

Limitations: Reliability depends on operator experience, equipment quality, and lesion location. The technique cannot assess deeper structures beyond the superficial dermis and should be integrated with clinical context.