1. Pigmented nevi (moles) 29 patients, 41 lesions 17 benign nevi 18 dysplastic nevi 6 melanomas Control: adjacent normal skin Richard Langley et al., Mass. General Hospital

2. Key features of pigmented nevi (in progress) Normal versus Malignant order disorder in epidermis, dermis regular network of cells disrupted cell borders polygonal or round irregular, atypical shapes nested pagetoid distribution of cells low contrast high contrast small, regular elongated, thickened dendrites symmetric eccentric melanin patterns Richard Langley et al., J. Amer. Acad. Dermatol. 45: 365-376, 2001

3. NORMAL HUMAN JUNCTIONAL COMPOUND DYSPLASTIC SKIN NEVUS NEVUS NEVUS Normal vs. benign pigmented lesions Richard Langley et al., J. Amer. Acad. Dermatol. 45: 365-376, 2001

4. NORMAL HUMAN LENTIGO MELANOMA SS MELANOMA SKINMALIGNAIN SITU IN SITU Normal skin vs. melanomas Richard Langley et al., J. Amer. Acad. Dermatol. 45: 365-376, 2001