The pathologic classification of appendiceal mucous cysts is divided into four types according to the concept of medical pathology: simple mucous cyst, mucosal hyperplasia, mucous cyst adenoma and mucous cyst adenocarcinoma. Simple mucous cysts: Appendiceal mucous cysts are formed when the mucus secreted by the mucosa of the appendix cannot be drained out due to narrowing or obstruction of the lumen of the appendix, and accumulates in the lumen of the appendix. Mucous membrane hyperplasia: The mucous membrane of the appendix is hyperplastic, causing increased secretion of mucus and enlargement of the appendiceal lumen. Mucous cystadenoma: It may be caused by chronic inflammation in the appendiceal lumen due to obstruction of the appendiceal lumen followed by fibrosis and scar formation, or mucous adenoma caused by adhesion and distortion due to a foreign body. Mucinous cystadenocarcinoma: it is a malignant tumor formed by malignant transformation of mucinous cystadenoma. If appendiceal mucinous cysts are found during clinical physical examination, it is recommended to actively seek medical treatment and follow the doctor’s instruction to treat accordingly.