A malignant soft tissue neoplasm that arises from the esophagus. Representative examples include Kaposi sarcoma, leiomyosarcoma, rhabdomyosarcoma, and synovial sarcoma. The disease is esophagus sarcoma (MONDO_0001204). Also known as: esophageal sarcoma, sarcoma of esophagus, sarcoma of oesophagus, sarcoma of the esophagus, sarcoma of the oesophagus, sarcoma, esophagus, sarcoma, oesophagus.