BACKGROUND Appendiceal mucinous neoplasm(AMN)is extremely rare.Since the disease does not manifest a characteristic profile of clinical symptoms,it is easy to misdiagnose and still difficult to diagnose without operation.Here,we report a case of low-grade AMN(LAMN)and summarize its clinical features,diagnosis,and treatment.CASE S UMMARY A 63-year-old postmenopausal woman presented with a history of right lower abdominal mass.The patient underwent laparotomy,which showed an appendiceal mucocele originating from the apex of the appendix,and a simple appendectomy was performed.The subsequent histological assessment identified an LAMN with no lymph node involvement and negative surgical margin.The patient received six cycles of chemotherapy after surgery,and to date,more than a year after the surgery,the patient remains in good health.CONCL USION A unified,standardized,detailed,and accurate pathological diagnosis is needed for LAMN,to facilitate selection of an appropriate surgical plan.In addition,the surgeon should record the details of the tumors in the surgical records in order to facilitate follow-up after surgery.