Appendix, Low grade appendiceal mucinous neoplasm

Low grade appendiceal mucinous neoplasm (LAMN) is an uncommon tumor of the appendix that represents a lesion with abundant mucin production. It is considered a neoplasm of unknown malignant potential.

Macroscopically, the appendix is dilated and mucin-filled. Tense distension and appendiceal wall dissection by mucin may invariably lead to rupture of the appendiceal wall. Mucinous adenocarcinoma is an important differential diagnosis to rule out in this context. Diagnostic clues that support LAMN include lack of high grade dysplasia and lack of desmoplasia.