Reactive nodular fibrous pseudotumor is a benign fibrous reactive lesion caused by fibroblasts and myofibroblasts. Reactive nodular fibrous pseudotumors are commonly found in the gastrointestinal tract and mesentery. Endoscopically, they are characterized by a broad-based submucosal elevation that is hard or tough, with a smooth mucosal surface and no mucosal bridges. In some populations, endoscopic ultrasonography may be performed with symptoms such as hypoechoic changes in all lesions and heterogeneous echogenicity in some areas. The tumor originates from the lamina propria, the submucosa. The tumor has clear borders and no envelope under the light microscope, and mainly shows proliferating spindle cells arranged in a disorganized manner with extensive collagenous degeneration of the mesenchyme, most of the spindle cells are small in size and long spindle-shaped, with elongated and deeply stained nuclei, no necrosis, and rare karyorrhexis; There is scattered chronic inflammatory cell infiltration, lymphoid follicle formation in some areas, and focal areas with calcium salt deposits. If the symptoms are severe or persistent and do not improve, the patient should go to the hospital for treatment.