This review provides a comprehensive coverage of hereditary malignant melanoma with emphasis upon its heterogeneity as well as newly developed biomarker investigations. The recently described familial atypical multiple mole melanoma (FAMMM) syndrome is featured. Particular attention has been given to findings of increased hyperdiploidy observed as an in vitro phenomenon in cultured skin fibroblasts from high-risk and FAMMM-affected subjects. The FAMMM genotype is complex in that it predisposes a patient not only to melanoma (cutaneous and intraocular malignant melanoma) but also to other histologic varieties of cancer, including cancer of the lung, pancreas, and breast. Attention is given to cancer surveillance and management programs for patients at increased risk for the several forms of hereditary malignant melanoma. This approach capitalizes advantageously upon employment of a knowledge of genetics and hereditary cancer syndrome identification, with particular attention to tumor associations.