Vertical ex vivo dermoscopy in diagnosing and differentiating skin lesions.

BACKGROUND: Publications on vertical ex vivo dermoscopy of skin lesions are sporadic and present only as case reports. OBJECTIVES: This study defines, describes, and determines the importance of structures visible by vertical ex vivo dermoscopy in the diagnosis of pigmented, benign skin lesions and their distinction between themselves, and in relation to other skin lesions. METHODS: The prospective, descriptive study was conducted in two University centers. Digital images of completely excised skin lesions, fixed in formalin before further processing, were evaluated dermoscopically. For the analysis of horizontal ex vivo dermoscopy, pattern analysis was used, while for the vertical section, a description of the visible structures was made. RESULTS: The research sample consisted of 80 benign pigmented skin lesions obtained from 73 patients. Histopathological diagnosis of the evaluated lesions included 59 nevi, 17 seborrheic keratoses, 3 angiomas and 1 clear cell acanthoma. Seborrheic keratosis had the most variable presentation on vertical ex vivo dermoscopy. By analyzing the vertical section of the evaluated skin lesions, the importance of vertical ex vivo dermoscopy in the diagnosis and/or differentiation of blue nevus, seborrheic keratosis and angioma from other skin lesions was noted. STUDY LIMITATIONS: Small number of analyzed lesions, and inclusion of Caucasian patients only. CONCLUSIONS: Vertical ex vivo dermoscopy can contribute to the distinction between different pigmented benign skin lesions, as well as to their differentiation from other skin lesions. Furthermore, vertical section enables more accurate assessment of additional, descriptive lesional characteristics.