Since the immunostaining, abnormal gene, and abnormal chromosome profiles of AMSF tissues are non-specific, the diagnosis of these tumors rests mostly on patient presentation and tumor histopathologic grounds. AMSF may be confused with other myxoid-rich soft tissue tumors such as myxoid liposarcoma (MyxLPS), myxofibrosarcoma (MyxoFS), and extra-skeletal myxoid chondrosarcoma (EMC). MyxoFS tumors more often occur in a proximal rather than<unk>  location, consist of more prominent capillary vessels, and lack inflammatory and VRS-like cells. MyxLpS tumors consist of a monotonous cell population arranged in discrete myxoid-cellular clusters with conspicuous thin branching capillaries in a "chicken-wire pattern". EMC rumors: contain an epithelioid/rounded cell population arranged in single cells, clusters, or linear cords; lack VRS-like cells; and have neoplastic cells that express diagnostic fusion genes involving the NR4A3 gene fused with either the EWSR1 or TAF15 gene. Some nodular fasciitis and proliferative fasciitis lesions may have myxoid areas but unlike AMSF tumors are rapidly growing, contain ganglion-like cells with only rare inflammatory cells, and may regress without treatment. Other lesions that frequently present in<unk>  areas of the extremities such as hemosiderotic fibrolipomatous tumor, epithelioid<unk> , synovial<unk> ,<unk>  fibromyxoma, giant cell tumor of tendon sheath, and clear cell<unk>  are usually distinguished from AMSF based on their clinical presentations, gross pathologies, histopathologies, and/or neoplastic cell expressions of marker proteins, abnormal chromosomes, and/or abnormal genes.
Acral myxoinflammatory fibroblastic sarcoma
Superficial acral fibromyxoma
Peripheral ossifying fibroma
Juvenile hyaline fibromatosis
Aggressive infantile fibromatosis
Aggressive fibromatosis
Diffuse infantile fibromatosis
Juvenile active ossifying fibroma