Case Number : Case 1717 - 27 December - Dr Uma Sundram Posted By: Guest

Here you have a nice case from Dr Uma Sundram, her final one for 2016.

Cheers, Geoff Cross - DermpathPRO Projects

?dysplastic naevus ?odd benign hyperpigmented naevus

Atypical melanocytic lesion of special sites?i think its a benign compound nevus of special sites ,specially regarding the young age.

Some large round nest remotely like the nests of nested melanoma but I think this is a benign lesion...compound nevus. 

Dermoepidermal Junction Nevus

I’m definitely not at ease with this lesion. Sharply circumscribed melanocytic nests of varying size and shape are asymmetrically distributed along dermoepidermal junction, located predominantly at the tips and occasionally at the sides of rete ridges. On the other hand, patient is a young adult and there’s no evidence of chronically sun damage. I favor nested melanoma since I think this lesion would not have been excised if it had not the clinical and dermoscopic characteristic features of melanoma.

I would prefer diagnosis of junctional nevus 

As Robledo I found this lesion challenging. Cytological atypia is minimal/non existant  but architectural worrisome features are present. This is for me a dysplastic nevus (mild cytological atypia) the limits are apparently compromised so should suggest re-excision (as all experts remark all the time). Nested melanoma, as described in Kutzner's paper is typically a neoplasm of the adult/elderly has cytological atypia and sometimes we can see single melanocyte distribution (at least focally). On the other hand, I am never against performing molecular studies in difficult lesions without consensus among colleagues.

yes, minimal atypia with no prominent nucleoli

Unusual large nests, but no sufficient atypia.. 

I think I will go for a nevus of special site. The shoulder has been added to a long list of atypical site nevi (Am J Dermatopathology, December 2016)

I think this is a benign lesion with architectural atypia. I was not aware that shoulder is a special site. Mona, thanks for the reference.

We too thought unusual but benign nevus with architectural atypia in a young patient. We did not think this was melanoma but the large nests gave us pause.

Not a rare case but one that we all have struggled with from time to time!

Happy New Year, everyone! See you in 2017.

Thanks for sharing this case.. I find melanocytic lesions too stressful.. it's great learning here.. 

Happy new year Uma. Soon!!