Based on their presentation and pathology,<unk>  tumors can be very difficult to differentiate from some cases of desmoid tumors, nodular fasciitis, and low-grade fibromyxoid sarcomas. Relative to the latter three tumor types, however, the presence of tumor neoplastic cells that: 1) express the MUC4 marker protein and a FUS-CREB3L2 fusion gene or an otherwise rearranged FUS gene strongly suggest that the tumor is a<unk> ; 2) express the EWSR1-CREB3L1 fusion gene suggest that the tumor is a<unk>  but in any case is unlikely to be a low-grade fibromyxoid sarcoma. 3) express a FUS-CREB3L2 fusion gene is more likely to be a low-grade fibromyxoid sarcoma than a<unk>  (i.e. the FUS-CREB3L2 fusion gene is present in >90% of low-grade fibromyxoid sarcomas but only ~20% of<unk>  tumor cells); or 4) express an EWSR1-CREB3L1 or EWSR1-CREB3L2 fusion gene is likely to be a<unk>  tumor.<unk>  tumors have also been mistaken for rare types of other sarcomas that sometimes have epithelioid features such as mesenchymal chondrosarcomas, Ewing sarcomas, osteosarcomas,<unk>  variants of rhabdomyosarcoma, or leiomyosarcomas. They also may be mistaken for certain metastatic carcinomas such as signet ring cell carcinoma and lobular forms of breast cancer. Extensive immunohistochemistry analyses can help to differentiate these tumors from<unk>  tumors.
Sclerosing epithelioid fibrosarcoma
Angiomyofibroblastoma
Perivascular epithelioid cell tumour
Low-grade fibromyxoid sarcoma
Lymphoepithelioma-like carcinoma
Multinucleate cell angiohistiocytoma
Undifferentiated pleomorphic sarcoma
Plexiform angiomyxoid myofibroblastic tumor