Mucinous Cystadenoma, Appendix

Synonyms

Adenoma of the appendix; Low-grade appendiceal mucinous neoplasm (LAMN); Low-grade appendiceal mucinous tumor

Definition

Appendiceal adenomas are defined as lesions that are confined to the appendix with no evidence of invasion beyond the muscularis mucosae.

Appendiceal adenomas are of two main types. The most common type involves the appendiceal mucosa in a widespread, circumferential fashion. In these, excessive secretion of mucus by neoplastic epithelial cells within the confined appendiceal lumen frequently gives rise to cystic dilatation, creating a mucinous cystadenoma. Less commonly, adenomas of the appendix grow as localized, pedunculated, or sessile lesions.

Some authors recommend not using the term “cystadenoma” anymore, since cystic change does not indicate a separate disease category.

The lesion may contain either low-grade or high-grade dysplasia.

Clinical Features

• Incidence

  Appendiceal tumors represent less than 0.4% of all intestinal neoplasms. The most common...