Description: Histology

History:

 Lesion on the back noted during a skin examination. Patient had a past history of 2 melanomas. Was this a regressing solar lentigo or a melanoma in situ?

This was a melanoma in situ with atypical melanocytes in nests and along the Dermoepidermal junction.

Dermatoscopically there was a thickened network with grey dots of regression and polygon formation.

Below is a video on solar lentigo for comparison.