Appendiceal mucinous cystadenoma has a peak incidence age of 61-70 years old, with atypical hyperplasia or adenomatous polyp of the glandular epithelium, and various clinical manifestations, which is mainly treated by surgery. 1. Age of onset: appendiceal mucinous cystadenoma is a rare benign tumor of the appendix, accounting for only 0.3% of appendectomy specimens, with a peak age of onset of 61-70 years, a male-to-female ratio of 1:4, and an average age of onset of 55 years. 2. Pathology: the glandular epithelium of appendiceal mucinous cystadenoma showed atypical hyperplasia or adenomatous polyp, with atypical glandular infiltration in the wall of the appendix and crossing the mucosal muscle layer. 3. Clinical manifestations: the clinical manifestations of appendiceal mucinous cystadenoma are different, there may be no clinical symptoms, or it may be manifested as the symptoms of acute appendicitis, or the patient may consult the doctor because of touching the abdominal mass. Appendiceal mucinous cystadenoma can be complicated with acute appendicitis, intestinal torsion, intestinal necrosis, intussusception, intestinal obstruction, secondary infection of the cyst and hemorrhage, which will cause corresponding clinical manifestations. 4. Treatment: mainly surgical treatment, which can be resected under laparoscopy. Patients with appendiceal mucinous cystadenoma should go to the hospital in time, and standardize the treatment under the guidance of doctors.