Case Number : Case 1637 - 4 October Posted By: Guest

Another great case from Dr Uma Sundram.

Don't forget to check out Dr Walter Mooi case from the Manchester Dermatopathology Case which is the current Case Video of the Week, well worth the visit.

Cheers, Geoff Cross

AV and Data Limited - DermPathPro Projects

This is a thin lesion that has heterogeneous features. We have an area better seen in pic 3 that looks like a junctional nevus that from my point of view has at most mild dysplasia (should see the slide to better assess). Then the nests become larger and expansile towards the center and they coalesce acquiring a complex architectural organization, we can see some areas of retraction artifact surrounding some of the nests. The melanocytes are mildly to moderately atypical and surround adnexae, there is a single non-atypical mitosis in the last picture and a florid lymphocytic reaction is also evident. The clinical setting is worrisome. I would perform a nuclear melanocytic marker in order to better asses the breslow. But my diagnosis would be MELTUMP favouring benign behaviour and suggest follow up, It would not bother me to perform Fish or CGH in this case.

Agree with most of the comments made above. I am worried with the deep mitosis in the last figure, brisk lymphoid infiltrate and the confluence of nests. p16 may help. I would recommend complete excision, favouring a melanoma.

I can see an atypical lesion with "asymmetry and border notching" clinically and large nested melanocytes with small but atypical nuclei and few or no pagetoid spread on histopathology. In this person (57 yo) I think this is an "in situ" nevoid melanoma. This is a good case to be supported by FISH or CGH.

Difficult but based on clinical and what we see I favour a relatively thin SSMM arising in the setting of a mildly dysplastic naevus.

Extremely difficult case and great to see the excellent discussion! We too favored a melanoma arising within a dysplastic nevus and MyPath was positive, in the melanoma range. The deep mitosis, sheet like growth pattern and epidermal consumption were all concerning features for us.