1. Skin Pathology, Case 3 40 year-old female with no significant past medical history presents with a 1 cm pigmented lesion on the back. The borders are irregular and the color is variegated.

2. Describe the skin lesion

3. The "ABCDs" are helpful in the diagnosis of melanoma. A: asymmetry- one side or half does not look like the other B: border irregularity C: color-black, or much darker than patient's other moles D: diameter > 6 millimeters

4. Close up Describe the skin lesion

5. Close up This melanoma is darker than any of the other pigmented lesions present. On close-up the lesion is seen to have an irregular border and also has uneven coloration with some darker areas.

6. Describe the skin lesion

7. This darkly pimented lesion was suspected of being a melanoma. It is shown undergoing excisional biopsy. When feasible, the entire lesion should be removed and submitted for histopathological diagnosis. This melanoma had a thickness of 0.6 mm. The patient was later treated with a wide local excision.

8. Describe the skin lesion

9. The lesion (melanoma) is asymmetrical, has an irregular border, very dark and irregular color, and was much larger than 6 mm in diameter.

10. Describe the skin lesion

11. Nodular melanoma. This lesion demonstrates all of the ABCDs.

13. Epidermis with focal ulceration Nests of malignant melanocytes within dermis

14. Describe the high power findings

15. Clusters of malignant melanoma cells (in dermis) Pigmented melanoma cells

17. Irregular nests of malignant melanoma cells within epidermis Nodular aggregates of melanoma cells in dermis

18. Irregular nests of malignant melanocytes in epidermis