Sorry. Ian Katz should have been on today. Here is a case I saw recently in a young male with a history of a lesion on his abdominal wall which had only been there for 3 or at the most 5 years. He had some total body photography images taken when he was 15 years old. He is now 26.
What do you think of this lesion? Happy to reassure him or would you cut it out? He has quite a few other clinically "atypical" nevi but none quite as large as this one.

Dr Cliff Rosendahl said...
Fantastic case with baseline and follow up images.
Chaos - absent. Leave!
A melanoma of this size would not be symmetrical!
This proves that 'congenital-type' naevi need not be present at birth.
Thanks Ian!

Dr Ian McColl said...
Glen, the advantage we have here is the total body photographs taken when he was 15 years old. There are none from the intervening time and he has not been regularly reviewed by anyone. This lesion was a standout in terms of it's size but is it symmetrical? Does it have any dermatoscopic clues to melanoma that would make you excise it?

Dr Alan Cameron said...
Great case Ian!

How do we weigh up the clear evidence of a new and enlarging lesion with a clue to melanoma (grey structures) and enough peripheral brown clods north and NW to at least raise the question of asymmetry against the strong impression of symmetry when viewed from a distance and the young age.

Banky et al found 126 changed and 155 new lesions in patients under 30 for a total of 4 melanomas. So around 70 benign for each melanoma.

Overall 18 melanomas were found using TBP in this study, only 4 were new lesions, 14 were changed. This is not surprising; there were more melanomas that were inconspicuous at initial photography that became apparent over a few years, than totally new ones.

Dr Ian McColl said...
I have put up the histology. Choose from Melanoma, Congenital nevus, Severely dysplastic compound nevus.

Dr Cliff Rosendahl said...
The histo is not a melanoma and not a congenital naevus, It's a compound naevus
Nests exceed single cells
Melanocytes mature as they descend (at least the very deep ones do)
It better be a benign compound naevus!

Dr Cliff Rosendahl said...
Keith the first histo slide has an interesting DE junction but can't assess well at low power. This is a great case and it may even provoke immuno-stains to assess maturity but on what I can see in those images I would think it is a compound naevus. I'll email Ian K and ask him to look

3:03 PM
Ian Katz said...
This is a real tough case histologically. That first slide does have quite a lot of flattening but there is also some scarring so that may be a regenerative area. The other histo slides show atypia in some areas but other areas resemble a congenital naevus.

Probably congenital naevus with scarring but would really have to examine carefully

Immunoperoxidase I find unhelpful in these cases

3:11 PM
Dr Ian McColl said...
OK Reported by my pathologist as severely dysplastic compound nevus. He felt the dermoepidermal junction changes were not those of a congenital nevus.
I see Cliff kept the dysplastic word out of his assessment but there is quite a bit of cytological atypia of those basal melanocytes and some but not all of the nests.
There was quite a bit of melaninin melanophages in the centre as well.

3:34 PM
Ian Katz said...
in other words it is a melanoma

Dr Ian McColl said...
I thought it was benign on dermatoscopic grounds when I saw him but he said this was still growing and changing by becoming darker centrally. The fact that it was such a standout and relatively new meant I really could not have left it. When patients say things are changing then unless i am 100% sure it is benign I usually excise. I did not need much urging to remove this one.

Harald Kittler said...
I changed my opinion after I had a closer look at the histopathology. First of all there is a banal nevus present for sure. No doubt about that! the fact that it was not present at age 15 doesn't mean anything. These type of nevi tend to appear in early childhood until late puberty and have a "congential pattern" on histopatology. The only question that remains is: IS there a melanom in situ in the center of the nevus or is this trauma related. In the absence of any convincing history of trauma you probably have to sign it out like melanoma in situ developing in a nevus. A limited lentiginous proferation of melanocytes at the junction is common over these types of nevi! This is probably too much (in the absence of trauma)
NEvi and MELANOMA are 2 different things and the fact that both may appear together does not mean they are part of a spectrum. I don not understand why this cannot be understood!
In sum: Most parts of this lesion are a banal nevus, no doubt,but a melanoma may develop in a banal nevus and this fact doesn't make the nevus "dysplastic" in retrospect.

5:35 PM
Harald Kittler said...
BTW: Melanoma in congenital nevi may develop anywhere (in the center like here or at the periphery), melanoma in Clark nevi usually develop at the periphery!

5:38 PM
Dr Cliff Rosendahl said...
Thanks harald and thank you for clarifying the insitu melanoma arising in naevus scenario. Do you think that there are dermatoscopic clues to the insitu melanoma? Do you think the appearance at the centre of this lesion relates to melanoma or is that all part of the dermatoscopic apprearance of the congenital naevus?

5:48 PM
Harald Kittler said...
Sure there are clues: Gray dots! the overall appearance is symmetric because the melanoma (if it is one!) happened to develop in the center of this lesion.

Harald Kittler said...
Gary, this case is different! This is not a nevus of the lentiginous type of the elderly. The content is always improtant in dermatscopy.

7:46 PM
Dr Cliff Rosendahl said...
This is a very good case Ian. We still don't know if there is melanoma there but it has made me aware that if melanoma arises in the centre of a congenital naevus there may be symmetry for a while. Clues need to be assessed in congenital naevi even in the absence of chaos!