Melanoma and melanoma in situ: build a better diagnosis through architecture

Conventional microscopy has remained the gold standard for melanoma diagnosis for several decades, and a diagnosis of melanoma is optimally based on a summation of microscopic features (criteria) that are evaluated as objectively as possible by an experienced histopathologist. Most pathologists and dermatopathologists assess multiple criteria before arriving at a diagnosis of melanoma, but the diagnosis remains somewhat subjective as different interpreters employ similar criteria but assemble them in very different ways. Due to the subjective aspects of the microscopic diagnosis of melanoma, considerable interobserver variability exists, even among expert diagnosticians. This article includes a brief analysis of the reproducibility of a diagnosis of melanoma with a comparison of architectural and cytological criteria. There is evidence to suggest that architectural attributes hold greater reproducibility over cytological features in the diagnosis of melanocytic neoplasms. If architectural criteria outperform cytological criteria in terms of reproducibility, then architectural features should probably be given preference over cytopathological aberrations in daily diagnosis. The author forwards four steps that can be used in the evaluation of any melanocytic neoplasm as well as an approach to melanoma diagnosis in which architectural features are emphasized.