Dermatoscopy turns histopathologist's attention to the suspicious area in melanocytic lesions.

Abstract

Histopathologically, the diagnosis of nevus-associated melanoma or melanoma close to a common nevus can be missed if the specimen is cut in a nonrepresentative area or if the section shows only the associated common nevus. To find out whether dermatoscopy of suspicious areas within a nevus can improve the histological diagnosis of malignant melanocytic lesions of the skin. The study was based on dermatoscopic images of more than 2000 benign and 115 malignant pigmented lesions and a collection of corresponding histopathologic slides. The dermatoscopic images and the corresponding histopathologic diagnoses were compared. In case of differences, the histopathologic findings were reevaluated and compared with the dermatoscopic findings. Three cases were identified in which melanoma could have been histopathologically missed as a result of improper sectioning. After the dermatoscopic findings were evaluated, the specimens were reembedded and further sections were obtained. Finally, nevus-associated melanoma or melanoma close to a common nevus was diagnosed. Specific dermatoscopic patterns of malignancy can be found in highly suspicious areas, eg, broadened networks, radial streaming, pseudopods, or dots located at the periphery. The dermatoscopic-histopathologic correlation can improve the diagnosis of melanoma. Therefore, the clinician should point to the most suspicious area with a drawing or image, and the suspected diagnosis of melanoma and the history of the lesion should be also mentioned.