Case Number : Case 580 - 29 Aug Posted By: Guest

I don´t see cigar-shape cells, although vascular changes and stroma make me think in [b]angioleyomioma.[/b]

Angioleiomyoma vs Myopericytoma

Thought of myopericytoma (solitary myofibroma)

Elongated vascular channels - The cells in the solid areas are ovoid plump spindled to round ones. The histopathological spectrum of myopericytoma is wide including angioleiomyoma like lesions. It can be painful at times though the classical painful skin tumours (BENGAL) does not include it. DD angioleimyoma. Desmin can be helpful (can be positive in angioleimyoma but usually negative myopericytoma).
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Solitary myofibroma (good example showing zonation, hyalinization)

[font=georgia,serif]Some have used the term "p[size="2"][size="2"]erivascular myoma" for a histopathological continuum of three groups of tumours – myofibroma in adults, glomangiopericytoma, and myopericytoma – showing perivascular myoid differentiation.[/size][/size][/font]

This is a very difficult case and one that would have caused me great problems had it not been given to me as a present from a soft tissue tumor expert with the diagnosis known!!! Sadly soft tissue tumors have never been my strong point. I remember many years ago Chris Fletcher was my Fellow and we looked after the dermatopathology and soft tisuue tumor services. After a couple of years Chris looked up shyly at me during a signout and said "perhaps you should take care of the dermatopathology and leave the soft tissue tumors to me". My relief was palpable!!
The tumor is an epithelioid sclerosing fibrosarcoma. This variant of fibrosarcoma is characterized by a fairly uniform population of epithelioid cells sometimes with clear cytoplasm arranged a compressed strands or nests associated with a very dense and hyalinized stroma. Bone formation may be a feature. Vimentin is consistently present and some tumors focally express EMA, S-100 protein and NSE
This is the only case of this exceedingly rare tumor that I have seen!!

Thanks Dr McKee. I did notice that the cells in the solid areas are arranged in cords and strands and surrounded by conspicuous collagenous stroma. I understand it is low-grade one and the DD includes it. Was it an extension of a deeper tumour or it arose in damaged skin (burn or radiation) or otherwise? Once again, immunohistochemical studies can be helpful.

Amazing ,, just amazing!!! Many thanks Dr McKee,,,

I have no other information but it something to remember.

Thanks Dr McKee.