Case Number : Case 134 Posted By: Guest

Phillip McKee - Overseas consultations (Sedona, Arizona,USA) Wrote:

This is another of these difficult soft tissue tumors which rarely present to the dermatopathologist although this lesion typically arises in the subcutis. The clue is the metaplastic bone in the capsule. The diagnosis is an ossifying fibromyxoid tumor. The tumor cells are dispersed in a myxoid stroma. You see Richard, when you think of the correct diagnosis, don't dismiss it. It is a bit like doing multiple choice questions. The first answer that you think of is usually your best shot (well it was your second shot but a very good thought even though you dismissed it)!!

Submitted on 14/12/2010 18:52
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Richard Carr - Warwick (UK) Wrote:

How about ancient schwannoma? Looks encapsulated and you have the hyaline changes in the vessels. There is a soft tissue lesion called "ossifying fibromyxoid tumour" but I don't think it is that.

Submitted on 14/12/2010 17:56
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Juan Carlos Garcés - Hospital Oncológico / Hospital Luis Vernaza (Guayaquil Ecuador) Wrote:

You can have osseous metaplasia in a variety of mesenquimal tumors like sinovial sarcoma, malignant peripheral nerve sheath tumors, fibromatosis, among others. Low grade fibromyoid sarcoma could have osseous metaplasia too, so it is a good possibility

Submitted on 14/12/2010 13:41
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Eman El-Nabarawy - Cairo University (Egypt) Wrote:

My first impression is low grade fibromyxoid sarcoma vs myxofibrosarcoma.

Submitted on 14/12/2010 06:22
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Mona Abdel Halim - Dermatology Department, Faculty of Medicine, Cairo University. (Egypt) Wrote:

This is a very difficult case. I will give it a try. Well circumscribed spindle cell proliferation (? pseudo fibrous capsule). There is variably alternating loose myxoid areas and more dense or fibrous areas. I think there are also curvilinear vessels. I am thinking in low grade fibromyxoid sarcoma. DDx should include other fibrosarcomas with curvilinear vessels and myxoid stroma such as: Myxofibrosarcoma (low to intermidiate grade) and low grade myofibrosarcoma (myofibroblastic sarcoma). I am not sure if there is some metaplastic bone formation in the right half of the field. Since this is a spindle cell neoplasm the most important possibility is that I am totally wrong as this area in dermatopathology is the most difficult and challenging to me!!! Wish u all a happy day.

Submitted on 14/12/2010 05:49
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