<unk> , abbreviated<unk> , is a very rare type of<unk> -tissue sarcoma, that grows slowly and whose cell of origin is unknown.<unk>  arises mainly in children and young adults and can migrate (metastasize) into other<unk> s of the body, typically the lungs and the brain. Typically,<unk>  arises in muscles and deep<unk>  tissue of the thigh or the leg (lower extremities), but can also appear in the upper extremities (hands, neck, and head). While<unk>  is a<unk>  tissue sarcoma, it can also spread and grow inside the bones.
Alveolar soft part sarcoma
Angiomatoid fibrous histiocytoma
Epithelioid sarcoma
Mast cell sarcoma
Hemangiosarcoma
Oncocytoma
Mycetoma
Hemangioendothelioma