Case Number : Case 2124 - 31 July 2018 Posted By: Uma Sundram

I am debating whether this should be classified as cellular blue nevus or just blue nevus. The upper cellular portion doesn't have dumbell shaped deep extensions. But maybe strictly speaking I should classify as cellular blue nevus. 

I am worried about this lesion. 65 year old, sun exposed skin, there is a continuous proliferation of melanocytes with some nuclear atypia. I would suggest complete excision, i am worried about melanoma

I am also concerned.  We sometimes send borderline lesions for Myriad Mypath study to help us.  If this is a blue nevus, they tend to test far into the benign portion of the spectrum so might be helpful here.

I have a hard time evaluating the epidermal component. So I would do Melan-A and SOX-10 to see whether there is an increase of melanocytes in the epidermis. If there is significant increase of melanocytes along the dermal-epidermal junction, I would call it malignant melanoma. Since I am not quite convinced there is an overlying melanoma in situ / lentigo maligna based on the available figures, I would consider the entity below:

Epithelioid and fusiform blue nevus of chronically sun-damaged skin, an entity distinct from the epithelioid blue nevus of the Carney complex.

My first thought: benign blue nevus in a sun damaged skin. Agree with Anh about Melan A utility to valuate the intraepidermal melanocytic growth.

Great and extremely valuable comments. I too think this is a pre existing blue nevus on sun damaged skin. There is some atypia and given the age, I recommended excision. Mitf highlighted a small lentiginous junctional component.