Case Number : Case 374 Posted By: Guest

Phillip McKee - Overseas Consultations (Cave Creek, Arizona, USA) Wrote:

This is a challenging case and the clinical information is helpful. As you all noticed from the top right image, this is a melanocytic lesion. Figure 1 shows this to be huge lesion extending into the deep dermis and subcutaneous fat. If this were benign, one would expect a much more superficial lesion with obvious maturation and perhaps type C cells. The image at the bottom left is from near the top of the lesion, that on the lower right is the deep aspect. This is a small cell melanoma (which mimics type B cells) and contrasts with nevoid melanoma which mimics type A cells

Submitted on 15/11/2011 12:46




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Marcela Saeb Lima - INCMNSZ (Mexico City) Wrote:

compound melanocytic nevus with senescent features, there is maturation with depth, although cells are not spindled they are smaller, no mitotic activity, and as Mona said there are no expansile nests...

Submitted on 15/11/2011 11:49




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Eman El-Nabarawy - Cairo University (Egypt) Wrote:

Thought of ancient nevus.

Submitted on 15/11/2011 11:07




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Mona Abdel Halim - Dermatology Dept. Cairo Univ. (Egypt) Wrote:

I meant showing almost no CT in between, SORRY!!!

Submitted on 15/11/2011 10:20




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Mona Abdel Halim - Dermatology Dept. Cairo Univ. (Egypt) Wrote:

What about a desmoplastic nevus.. We don't have any mitosis, and I think we have pseudovascular spaces rather than intravascular nests. I think nevoid melanoma has a different morphology with expansile masses showing almost CT in between, I don't think it is the case here.

Submitted on 15/11/2011 10:18




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A Bansal - BCU HB (North Wales) Wrote:

I found this to be a challenging case. I think this is a naevocellular lesion and my differential diagnosis includes deep penetrating naevus (although not much pigment) and malignant melanoma, naevoid-like. Needs IHC - Ki67, cyclin D1, S100 protein, HMB45 etc.

Submitted on 15/11/2011 07:25




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Sasi Attili - (UK) Wrote:

Quite a tough one for me. There are naevoid nests in the upper reticular and papillary dermis (with giant cells and slight pleomorphism)and in the top left field there is also epidermal involvement. I would like to see the HP image of this. A few intravascular nests are also seen in the top right image. However the cells are much more monomorphic in the lower dermis, extending quite deep forming pseudovascular spaces. However I could be wrong and these could be fat cells with rimming of the neoplastic cells! (though I think this is unlikely given that these spaces are quite high up) There are no mitosis obvious to me, though the pattern of cell growth (in deep dermis and infiltrating between collagen)and the age to me are worrying. I would like to see immuno S100, LCA, Melan A, CD 34, CD 31, EMA, CK. But based on H&E I would suspect a melanocytic lesion. Given the lack of mitosis I am not convinced this is a melanoma but the age is in favour of the latter. Would quite like to see HMB 45 to see if there is any stratification ?Naevoid melanoma? ? MELTUMP? Obviously based on immuno, differentials include lymphoma, Angio sarc, Carcinoma, Metastases etc but cells do not look atypical enough to me.

Submitted on 15/11/2011 07:12