Reflectance confocal microscopy evaluation of pigmented lesions on tattooed skin

The evaluation of pigmented lesions on tattooed skin poses a diagnostic challenge for dermatologists, as a nevus may be partially or completely obscured by tattoo pigment. Because of incidences of melanoma arising from tattooed skin, the current gold standard is to biopsy these lesions. Reflectance confocal microscopy (RCM) is a noninvasive imaging modality used in the diagnosis and management of skin diseases that may allow for diagnosis, while preserving the tattoo design. Retrospective chart review was conducted to identify pigmented lesions on or near tattooed skin that were evaluated with RCM. Confocal characteristics and diagnoses were recorded and analyzed. Nineteen lesions from 15 patients were retrospectively reviewed. Tattoo pigment did not hinder evaluation and diagnosis of pigmented lesions on RCM. About 94.7% of lesions were diagnosed as benign melanocytic nevi by an expert confocal reader. One lesion was confocally diagnosed as melanocytic nevus with atypia but was found to be an inflamed melanocytic nevus on histology. Tattoo pigment particles were differentiated from other hyper-refractile entities by an expert confocal reader based on size, morphology, and clinical correlation. RCM may provide a solution to the diagnostic challenge of pigmented lesions on or near tattooed skin.