Case Number : Case 752 - 3rd May Posted By: Guest

DDX: epithelioid angiosarcoma, AFX, acantholytic poor differentiated SCC

There is a grenz zone between nonatypical epidermis and the neoplasia, against a diagnosis of SCC. Also, the great cellularity and absence of marked pleomorphism do not favor a diagnosis of atypical fibroxantoma. Epithelioid angiosarcoma is my first choice too.

Agree, likely to be an angiosarcoma. Would do immunos: C31, CD34, AE1/AE3, S100 protein.

Anaplastic large cell lymphoma

My first impression is epithelioid angiosarcoma.

[color=#1C2837][font=arial, verdana, tahoma, sans-serif][size=4]Anaplastic large cell lymphoma[/size][/font][/color]

There are limited examples of soft tissue tumors with clinical presentation of a hemorrhagic mass. Taking into account the case history and the H&E pictures, I favor epithelioid angiosarcoma, although this is rare as a primary cutaneous tumor and I didn't find any focus of irregular vascular channels inside the solid sheets.
Immunohistochemistry will rule out or confirm the hypothesis put forward here.

This was two for the price of one.
The peripheral darker epithelioid shoulders expressed melanA and S100 strongly and were CD10 negative.
The central larger pleomorphic epithelioid cells were completely negative for melanA and S100 and strongly diffusely positive for CD10.
So my diagnosis: Collision of nodular malignant melanoma and AFX. You might just think the melanoma de-differentiated centrally (and acquired CD10) I guess it is academic!
Vascular, muscle, cytokeratin and p63 markers were all negative. I think ruling out anaplastic large cell lymphoma is a good suggestion I am still awaiting the CD30.

[font=arial,helvetica,sans-serif][size=4]Sorry...too late to join the fun discussion today!

Looking at the photos, I didn't get the impression this would be lymphoma given:
- its well-circumscribed nesting architecture superficially, in right hand smaller cell component.
- Its origin in the superficial dermis, as suggested by the downwards displacement of nodular solar elastosis to a position below the expansile tumor mass.

(Look forward to see if the CD30 shoots this down!).


I don't envy your dilemma of choosing between two very unlikely events (collision of two rare tumors vs. chance of melanoma losing S100 and MelanA simultaneously)...but a dilemma amenable to possible resolution via additional stains. Maybe a SOX-10 or MITF (melanoma), and/or procollagen (AFX) stain would help reveal the true deriation of the CD10 positive anaplastic cells. But academic, as you said, if it makes no clinical treatment difference.

If there is low mitotic activity (from photos, at least) in the anaplastic CD10 population, I would slightly favor the dedifferentiated melanoma option.[/size][/font]

CD30 is negative