A case of Pseudomyxoma Peritonei of an unexpected origin

Diagn Pathol. 2021 Dec 20;16(1):119. doi: 10.1186/s13000-021-01179-z.

Abstract

Background: Pseudomyxoma peritonei (PMP) is a complex and partially understood disease defined by mucin deposits in the peritoneal cavity, mostly of appendiceal origin caused by the rupture of a mucocele often containing Low or High grade Appendiceal Mucinous Neoplasm (LAMN/HAMN). Other origins include primitive ovarian mucinous cystadenoma or cystadenocarcinoma almost always with an associated teratoma, but to our knowledge no case of ovarian teratomatous appendiceal-like mucocele with LAMN has been reported as a cause of PMP.

Case presentation: A 25-year old female with infertility was diagnosed with an isolated left ovarian tumor in a context of PMP. Histological examination revealed an ovarian teratoma containing an appendiceal-like structure with mucocele and LAMN, without any associated lesion of the appendix on full histological analysis. Molecular characterization of the ovarian lesion showed co-KRAS and GNAS mutations, as described in PMP of appendiceal origin, while only KRAS mutations are reported in primitive ovarian mucinous tumor.

Conclusions: Detection of co-KRAS and GNAS mutations in our case of ovarian teratomatous appendiceal-like mucocele with LAMN shows that when PMP derives from a mucinous ovarian lesion (with histological proof of none-appendiceal involvement), it is probably of a digestive teratomatous origin, emphasizing the need to actively search for tetatomatous signs in a context of ovarian PMP.

Keywords: Appendiceal pseudomyxoma peritonei; KRAS / GNAS mutations; LAMN; Ovarian pseudomyxoma peritonei; Ovarian teratoma; Pseudomyxoma peritonei.

Publication types

  • Case Reports

MeSH terms

  • Adult
  • Appendiceal Neoplasms* / genetics
  • Appendiceal Neoplasms* / pathology
  • Female
  • Humans
  • Ovarian Neoplasms* / genetics
  • Ovarian Neoplasms* / pathology
  • Peritoneal Neoplasms* / diagnosis
  • Peritoneal Neoplasms* / genetics
  • Pseudomyxoma Peritonei* / diagnosis
  • Teratoma* / pathology