Sclerosing epithelioid fibrosarcomas are aggressive tumors that usually develop in adults and elderly individuals[7] or, in a small minority of cases, children.
[1] SEF tumors often occur in a shoulder, hip, or lower areas of the legs and arms or, less commonly, in a vital organ or other tissue location that may be in virtually any part of the body.
[7] SEF tumors tend to recur at the site where they are surgically removed, to metastasize to other tissues, and to have poor outcomes.
[7] Surgical resection of the primary or recurrent tumor with or without adjuvant radiation therapy has been the mainstay treatment for SEF.
[1] As defined by microscopic histopathologic analyses of hematoxylin and eosin stained tissue samples, SEF tumors vary from lower to higher cellular lesions.
The cells contain moderate numbers of mitochondria, abundant rough endoplasmic reticulum networks, large Golgi complexes, and cytoplasmic arrays of vimentin intermediate filaments.
The cells tend to be grouped into nests, sheets, cords, and/or single files embedded in an eosinophilic (i.e. more blue or purple compared to normal connective tissue because of excessive uptake of the hematoxylin stain), sclerotic (i.e. hardened) connective tissue background.
The connective tissue background contains irregular, thin-walled, distended blood vessels and may have foci of hyaline cartilage, bone formation, and necrosis (clumps of dead or dying cells).
[5] Immunohistochemical analyses find that the neoplastic cells in SEF tumors typically express MUC1,[12] vimentin, Bcl-2, CD99, and MUC4 marker proteins.
[13] The largest study to date tested 26 SEF patients for certain types of gene rearrangements in their tumors' neoplastic cells.
The chemotherapy regimens included one or more of the following drugs, doxorubicin, ifosfamide, docetaxel, gemcitabine, pazopanib, vincristine, cisplatin, cyclophosphamide, etoposide, and/or dacarbazine.
[8] Nonetheless, studies suggest that radiotherapy should only be administered in cases where surgery is impossible and/or has the potential to slow the progression of the disease[7] and all currently used chemotherapeutic regimens have generally been ineffective in controlling these tumors.