Abstract: Objective: To explore the pathological diagnosis features and differential diagnosis of one case of patient with solid pseudopapillary neoplasm (SPN) of pancreas occurred in the majus omentum,and to improve the understanding of extra-pancreatic SPN. Methods: One female patient was admitted to hospital because of abdominal mass found 20 d ago.The patient was diagnosed as multiple hysteromyoma by gynecological color ultrasound,and the results of abdominal ultrasound had no obvious abnormity.The patient underwent hysterotomy,and a well-defined mass in the majus omentum was found during operation,so the patient received hysterectomy and omental tumor resection. Results: The patient was confirmed as multiple hysteromyoma by the postoperative pathological examination.The patient was clearly diagnosed as SPN arising from the majus omentum on the basis of pathological characteristics and immunohistochemical staining results.There were no ectopic pancreas tissue arround the tumor and no SNP metastasis in examination of ultrasound and CT.No recurrence and metastasis were found in the follow-up of 3 years. Conclusion: SPN arising from the majus omentum is extremely rare.The tumor has clear boundary,typical morphology and immunohistochemical appearances.

Key words: hysteromyoma, majus omentum, pancreas, solid pseudopapillary neoplasm