Appendiceal tumours

Section: Emergency Curriculum: Curriculum, page 27

Lesion classification

• Epithelial tumors of the appendix
  • Mucinous appendiceal lesions
    • Nonneoplastic
      • Appendiceal mucocele
    • Neoplastic
      • Appendiceal mucinous neoplasms
        • Low-grade appendiceal mucinous neoplasms (LAMNs)
        • High-grade appendiceal mucinous neoplasms (HAMNs)
      • Appendiceal Adenocarcinoma (may be mucinous or non-mucinous)
  • Non-mucinous appendiceal lesions
    • Serrated polyps of the appendix
    • Appendiceal Adenocarcinoma
    • Goblet cell Adenocarcinoma
• Neuroendocrine neoplasms of the appendix

Peritoneal disease

• Pseudomyxoma peritonei
  • Clinical syndrome characterized by diffuse mucinous peritoneal involvement
  • Term that has been applied to peritoneal dissemination of a wide variety of mucin-producing invasive adenocarcinomas
  • Better to use the descriptive terms
    • Disseminated peritoneal adenomucinosis (DPAM)
      • Presence of abundant peritoneal extracellular mucin containing scant mucinous epithelium with little cytologic atypia or mitotic activity, with or without an associated appendiceal mucinous lesion
      • M1a
      • From ruptured LAMNs or, less commonly, a benign mucocele
    • Peritoneal mucinous carcinomatosis
      • Presence of peritoneal lesions that are composed of more abundant mucinous epithelium with the architectural and cytologic features of carcinoma, with or without an associated primary mucinous adenocarcinoma
      • M1b