Molecular histology on the diagnostic cutting edge between malignant melanomas and cutaneous melanocytomas (Review)

Abstract

In recent years, the screening accuracy of clinical dermoscopy has increased in the early detection of evolving atypical melanocytic neoplasms. However, the most dramatic cases of human malignant melanomas (MM), i.e. the fast-growing neoplasms, usually escape the classical clinical criteria of MM. As a result, a number of puzzling cases exhibit uncertain clues for MM. Thus, the risk of microscopic misdiagnosis is likely on the rise if the histological criteria are not fine-tuned. This review summarizes a conceptual classification of atypical melanocytic neoplasms grouped under the heading of melanocytomas. Some immunohistochemical markers are tentatively used as discriminators between fast-growing MM and melanocytomas. However, some differences seem to be more statistically significant than clinically useful due to extensive overlap in immunoreactivity from any case to case. A multipronged immunohistological screening is therefore welcome.