The more common mesenchymal tumors in the digestive tract include esophageal smooth muscle tumors, gastrointestinal mesenchymal tumors, and rectal carcinoid tumors. What is esophageal smooth muscle tumor? Esophageal smooth muscle tumor is the most common benign mesenchymal tumor in the esophagus, which can occur in any part of the esophagus, but the middle part is the most common, the lower part is the second most common, and the upper part is the least common. According to the level of origin of esophageal smooth muscle tumor, it is divided into mucosal smooth muscle tumor and intrinsic muscle smooth muscle tumor. What is gastrointestinal mesenchymal tumor? Mesenchymal tumor of the gastrointestinal tract is an aggressive tumor with potential malignant tendency. Its malignancy is classically assessed by tumor size and mitotic index (MI). If the tumor diameter.