Case Number : Case 2411 - 26 September 2019 Posted By: Iskander H. Chaudhry

Difficult. There is fibrosis in dermis( unusual in HN), and clinically doesnt fit. There are also definitive shoulder spreading of melanocytes. Favor Melanoma. 

I favor a dysplastic nevus - no junctional confluent growth or substantial pagetoid spread. 

Atypical nevus with halo reaction (Halo nevus).Follow up is recommended after complete excision.

Very atypical epithelioid melanocytic proliferation, I would favor a malignant melanoma.

I would call it either a dysplastic nevus or a nevus of special site in case its on the milkline

Hard to classify thin lesion, atypical, some uncertainty, but favouring benign. May have a deep penetrating type clone (Beta-catenin would be of interest). Provided it's fully excised that is the end of it for me. 

Dear All 

Yes this was a difficult case which I took a consensus opinion on and this is the final report! 

Skin with an asymmetrical compound melanocytic lesion. This melanocytic lesion is predominantly junctional with a few single melanocytic cells in the upper dermis amongst the inflammatory infiltrate. It is small (4mm in maximum diameter) and slightly raised. The junctional component is predominantly nested and the nests are mostly placed at the bottom of the rete ridges with sparing of the suprapapillary epidermis. The component cells are epithelioid, cytological atypia is random and mitotic figures are absent. There is no significant single cell ascent, there is a little lateral spread, there is minor and focal epidermal consumption and no ulceration.

The features are insufficient for a diagnosis of melanoma in situ and the appearances are those of a low to high grade (moderate to severely) dysplastic naevus, with regression; despite the lack of lamellar fibroplasia and elongation of rete is minimal. The lesion is completely excised and lies 1.7 mm from the lateral resection margin. 

Iskander