Appendiceal Mucinous Neoplasm with High Risk of Recurrence
Controversy
- Low grade mucinous neoplasm - WHO proposed alternate name
- Term proposed to encompass mucinous neoplasms with low and high risks of recurrence
- Proposed because all are composed of histologically identical adenomatous appearing epithelium
- We prefer not to combine these processes as their clinical behavior is quite different
- Mucinous neoplasm with low risk of recurrence has very low morbidity and mortality
- Mucinous neoplasm with high risk of recurrence has considerable morbidity and mortality
- Furthermore, the term could be confused with low grade adenocarcinoma
- This is an ordinary colonic type adenocarcinoma, which has a more aggressive course
- Mucinous carcinoma - proposed alternate name
- Term proposed as alternate to mucinous neoplasm with high risk of recurrence
- We prefer to reserve this term for neoplasms capable of metastasis to organs such as lymph node, lung and liver (parenchyma)
- Mucinous carcinoma of all GI sites behaves aggressively, with metastases
- Does ovarian involvement represent spread from the appendix?
- Alternative possibilities include
- Simultaneous primaries, perhaps due to a field defect
- Ovarian primary with spread to appendix in some cases
- No clinical importance to the distinction as long as:
- Frequent association of appendiceal and ovarian disease is recognized
- Frequent association with pseudomyxoma peritonei is recognized
