Low-Grade Fibromyxoid Sarcoma is my spot.

Why not a low grade dedifferentiated liposarcoma? There is an atypical lipoblast in last fig.

...if deeply seated of course...

I also though of dedifferntiated liposarcoma

The location would be very unusual for dedifferentiated liposarcoma. Strictly speaking, lipoblasts are characterized by fat vacuoles indenting the nucleus like scalloping. So I am not convinced that's a lipoblast. 

The "lipoblasts " and other large cells would be very unusual for low-grade fibromyxoid sarcoma, but MUC4 would help.

The orange stained collagen is really unusual. But I think Dr. Carr explained one time why it looks so funny. But I am still not accustomed to look at that. Maybe some kind of atypical fibrous histiocytoma? How deep is this lesion?

Neurofibroma?

Agree, neurofibroma.

But the tumor is also positive for EMA with a  long cytoplasmic dendritic pattern. CD34 displays a whorling  pattern. Neurofibroma is usually negative for EMA. So there is another component in the tumor, namely perineurioma I think.

In summary:

Hybrid tumor: NF and perineurioma?

The French use Saffron in the H&E stain. Very chic! Nice fingerprint pattern on CD34.

Distinguishing neurofibroma from desmoplastic melanoma: the value of the CD34 fingerprint.

Thanks for the article Richard. This is actually a hydrid nerve sheath tumor (Schwannoma/Perineurioma) showing focal degenerative atypia. This is definetely and underrecongnized entity. I have made a small table that recapitulates the main features that we use to diagnose hybrid nerve sheath tumors. This is based on the two biggest series reported to date. Hope is useful.

Hybrid Nerve Sheath tumors.tif

Thanks for your many learning points, Richard and Raul!