A rare pseudomyxoma peritonei with a MSH2 variation of unknown significance and two mutation carrier family members

Pseudomyxoma peritonei (PMP) is known to originate in the appendix and peritoneal tissue, including the ovary. The pathogenesis of PMP is less understood than that of colon and ovarian cancer. Lynch syndrome (LS), or hereditary nonpolyposis colorectal cancer (CRC), is characterized by mutations in the mismatch repair (MMR) genes and by its development in multiple extracolonic sites (mostly endometrium) [1-3]. LS accounts for approximately 3-5% of CRCs; patients with LS have a 60-80% lifetime risk of CRC [4,5]. The appendix is a small organ connected to the cecum, connecting the small and large intestines. PMP and LS have not been studied extensively owing to their rare occurrence [6]. However, identifying a germline mutation carrier has a prophylactic advantage of better