Background Synchronous ovarian/appendiceal mucinous neoplasms sometimes occur in the absence of clinical pseudomyxoma peritonei (PMP), which raises a question about whether the 2 tumors could be independent.
Methods We identified 11 cases of synchronous ovarian/appendiceal mucinous neoplasms without PMP and subclassified them into groups 1 and 2 based on the presence or absence of microscopic peritoneal/ovarian surface mucin deposits. A 7-marker panel (CK7, CK20, CDX2, PAX8, MUC1, MUC2, and MUC5AC) immunohistochemistry was performed on both tumors.
Results Between the 2 groups, there were no significant differences in age, laterality, size, and histology of ovarian/appendiceal tumors. In group 1, 2 of 4 cases developed PMP later, and both had ovarian surface and contralateral ovarian involvement and appendiceal perforation with microscopic mucin deposits on the peritoneum. No patients in group 2 developed PMP. All group 1 cases showed a high degree of concordance of immunoprofile between the synchronous tumors, with an identical expression of appendiceal pattern in greater than 90% of the markers. In group 2, only 1 of 7 cases showed concordance in all markers.
Conclusions If peritoneal mucin deposits present, even microscopic and acellular, the synchronous tumors are most likely of a single appendiceal origin. Otherwise, they are more heterogeneous, and some may be truly dual primaries.
- Mucinous neoplasm
- Appendiceal tumor
- Ovarian tumor
- Synchronous tumors
- Pseudomyxoma peritonei
Statistics from Altmetric.com
The authors declare no conflicts of interest.
If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.