History: 4146ri This lesion on an elderly man's back looks suspicious with variable pigmentation and pink areas suggestive of regression. The lesion has not been treated before. Possible melanoma or other regressed pigmented lesion eg Dysplastic lentiginous junctional nevus of Kossard. Shave biopsy taken of the pigmented area at the base.

Description: Regression

Comments: Sections show a shave biopsy of a Level 1 superficial spreading malignant melanoma. It comprises a proliferation of atypical melanocytes forming irregular coalescing nests in the basal epidermis. There is focal upward epidermal spread. Some extension down hair follicle epithelium is also noted. There is no evidence of dermal invasion, however, there is evidence of regression.