ENO2 and malignant peripheral nerve sheath tumor: The malignant schwannomas are more prevalent in females (66.7%); the average age is 50.3 years old; the average tumor size is 57.5 mm; they are located on average 36 cm away from the incisor teeth; the most prevalent symptoms are dysphagia (70.0%), weight loss (20.2%) and palpitations (10.0%); the most used surgical procedure is enucleation of the tumor mass (66.7%); the immunohistochemical markers SMA, Desmin, CD34, CD117, NSE and DOG1 stained negatively on the malignant esophageal schwannoma end S-100 protein, Vimentin and NSE stained positively (Table 3).