myxoid tumor myxoid tumor a myxoid tumor is a connective tissue tumor with a "myxoid" background, composed of clear, mucoid substance. atrial myxoma this tumoral phenotype is shared by many tumoral entities: myxomas atrial myxoma odontogenic myxoma cutaneous myxoma intramuscular myxoma myxoid hamartoma aggressive angiomyxoma myxoid leiomyoma chondromyxoid fibroma myxoid neurofibroma nerve sheath myxoma (neurothekeoma) myxolipoma angiomyofibroblastoma myxoid leiomyosarcoma myxoid liposarcoma lipoblastoma myxofibrosarcoma myxoid cortical adenoma pleomorphic adenoma undifferentiated embryonal sarcoma plexiform angiomyxoid myofibroblastic tumor myxoid plexiform fibrohistiocytic tumor angiomyxolipoma (vascular myxolipoma) parachordoma acral myxoinflammatory fibroblastic sarcoma