Case Number : Case 2498 - 03 February 2020 Posted By: Iskander H. Chaudhry

Deep Penetrating Nevus.

Tattoo reaction.

Cellular blue nevus or deep penetrating nevus. 

Deep penetrating Nevus with ancient changes.

Please Dr Iskander, what's the diagnosis???

Please Dr Iskander, what's the diagnosis of 2489???

Please find the description and diagnosis from Dr. Chaudhry:

Dear all this was a challenging case shown to 4 pathologists - please see below: 

Skin with a dermal pigmented asymmetrical melanocytic lesion. The dendritic and epithelioid melanocytes extend into reticular dermis/ subcutis and have a cellular, nested and fascicular with abundant pigment. No junctional component is seen. Plump regular nests of melanocytes are noted. There is moderate cytologic atypia with some nuclear pleomorphism, small to medium-sized eosinophilic nucleoli; mitotic figures are inconspicuous with moderate mononuclear inflammatory cell infiltrate. There is an absence of maturation. The proliferation index is low.

The features are those of a deep penetrating naevus-like borderline tumor.

Eur J Dermatol. 2014 Sep-Oct;24(5):594-602.

Deep penetrating nevus-like borderline tumors: A unique subset of ambiguous melanocytic tumors with malignant potential and normal cytogenetics. Magro CM1, Abraham RM2, Guo R3, Li S4, Wang X1, Proper S5, Crowson AN6, Mihm M7.

DPN