Abstract: Objective To analyze the imaging features of Reactive nodular fibrous pseudotumor (RNFP), to improve the understanding and preoperative diagnosis of the disease, and to prevent clinical over-medication. Methods A number of databases such as MEDLINE, EMBASE, Web of Science, China Knowledge Network, and Wanfang Medical Network were searched to obtain cases of abdominal reactive nodular fibroids, and the corresponding clinical, imaging, and pathological features were summarized. Results 11 patients (35.5%) had a clear history of surgery, and 10 patients (32.3%) mentioned a more obvious history of abdominal disease.17 cases were single (54.8%) and 10 cases were multiple (32.3%).The most common lesions were the colon and appendix (10 cases), followed by the mesentery and small intestine, especially the terminal ileum (9 cases), omentum (5 cases), peritoneal wall (4 cases), hepatic sac, stomach wall and pancreatic circumference. Some RNFP can infiltrate the stomach and intestinal wall and ulcer or intestinal fistula formation (9 cases), some cases of lesions invade the pancreas and tail, spleen and left adrenal gland (1 case).The imaging manifestations of the disease and the pathological features of the disease, that is, the tumors appear as a disorderly arrangement of stellate or fusiform cells, with clear boundaries, with mucoid degeneration or hyaline degeneration, showing that keloid-like coarse collagen fibers are closely related. Conclusion RNFP is considered to be a rare abdominal fibrotic inflammatory lesion caused by abdominal, pelvic surgery or inflammatory stimuli. Because there is no specific imaging manifestation, it is easy to be confused with ovarian-derived diseases. Pathology and immunohistochemistry are diagnoses, gold standard. Surgery is the first choice of treatment.

Key words: MRI, Reactive nodular fibrous pseudotumor, Brenner tumor