CASE REPORT - First Case of Ovarian Metastases From a Primary Retroperitoneal Mucinous Carcinoma Associated With Teratoma, With KRAS and ERBB3 Mutations - Case Report and Literature Review

Q: Why are primary retroperitoneal mucinous carcinomas (PRMCa) difficult to understand?

PRMCa are exceedingly rare, with fewer than 80 documented cases, and molecular profiling is reported only rarely.

Q: What underlying origin is proposed for the presented PRMCa case?

The case suggests the PRMCa originated in a mature cystic teratoma, consistent with theories that PRMCa may develop from teratoma-related sources.

Q: Which mutations were identified and what is their significance?

Molecular analysis found a KRAS mutation and an ERBB3 mutation, described as the first documented ERBB3 mutation in this specific tumor entity.

Sep 23, 2026

Uploaded by Mabel

Primary retroperitoneal mucinous carcinomas (PRMCa) are exceptionally rare and remain poorly characterized, with fewer than 80 cases described and minimal molecular profiling reported. The literature suggests links to mature cystic teratomas or Brenner tumors, yet only two related primary retroperitoneal mucinous cases have been documented. This report presents a 66-year-old woman whose ovarian metastases arose from a PRMCa originating in a mature cystic teratoma, highlighting rapid metastatic progression and a maturation phenomenon, alongside KRAS and ERBB3 mutations.

LanguageEnglish

CategoryHealthcare

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Pages5

Reading Time13 min

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Abstract

Case report context and rarity

Proposed tumor origins and prior literature

Presented case: clinical course and metastases

Molecular findings and implications

CASE REPORT First Case of Ovarian Metastases From a Primary Retroperitoneal Mucinous Carcinoma Associated With Teratoma, With KRAS and ERBB3 Mutations: Case Report and Literature Review Jennifer Fallas, MD,*† Isabelle Salmon, MD, PhD,* Calliope Maris, MD,* María Gómez Galdón, MD,* Nicky D ’Haene, MD, PhD,* Jean-Christophe Noël, MD, PhD,* and Xavier Catteau, MD, PhD*† Abstract: Primary retroperitoneal mucinous carcinomas (PRMCa) are exceedingly rare and poorly understood neoplasms, with < 80 cases documented in the medical literature and molecular proﬁling hardly ever performed. Recent theories suggest that PRMCa might develop from mature cystic teratomas or Brenner tumors, mirroring their ovarian counterparts. However, only 2 cases of primary retroperitoneal mucinous tumors associated with teratoma have been reported in the literature to support this idea. In this paper, we detail an exceptional case: a 66-yr-old woman with ovarian metastases stemming from a PRMCa that originated in a mature cystic teratoma. The patient initially presented with a long-standing cystic mass in the retroperitoneum, diagnosed as a mucinous carcinoma after surgical removal. Following initial resection, the patient experienced rapid metastatic progression requiring aggressive treatment. Interestingly, the later ovarian metastases exhibited the full spectrum of architectural complexity observed in the initial lesion. This “maturation phenomenon,” frequently observed in ovarian metastases of mucinous tumors, remains enigmatic. Molecular analysis revealed a KRAS mutation along with an ERBB3 mutation, making it the ﬁrst instance of ERBB3 mutation being documented in this speciﬁc entity. This case underscores the importance of thorough data collection and continued research to improve our understanding of these rare tumors. From the *Department of Pathology, Hôpital Universitaire de Bruxelles, Université Libre de Bruxelles, Brussels; and †CurePath Laboratory, Jumet, Belgium. The authors declare no conﬂict of interest. Address correspondence to Jennifer Fallas MD, Department of Pathology, Hôpital Universitaire de Bruxelles, Université Librede Bruxelles, rue Meylemeersch 90, Brussels 1070, Belgium. E-mail: [jennifer.fallas@hubruxelles.be](jennifer.fallas@hubruxelles.be). Supplemental Digital Content is available for this article. Direct URL citations are provided in the HTML and PDF versions of this article on the journal’s website, [www.intjgynpathology.com](www.intjgynpathology.com). Copyright © 2025 The Author(s) . Published by Wolters Kluwer Health, Inc. This is an open access article distributed under the terms of the Creative Commons Attribution-Non Commercial-No Derivatives License 4.0 (CCBY-NC-ND), where it is permissible to download and share the work provided it is properly cited. The work cannot be changed in any way or used commercially without permission from the journal. DOI: 10.1097/PGP.0000000000001073 Int J Gynecol Pathol 􀀁 Volume 44, Number 5, September 2025 Key Words: ERBB3, KRAS, Pathogenesis, Primary retroperitoneal mucinous carcinomas, Teratoma (Int J Gynecol Pathol 2025;44:461–465) Primary retroperitoneal mucinous tumors are exceed ingly rare tumors almost exclusively found in women. These tumors form a distinct group of cystic neoplasms, characterized by their mucinous differentiation, which histologically mirrors mucinous tumors found in the ovary1 . Such similarities allow for a comparable classiﬁcation system, which categorizes these tumors based on their architectural complexity, ranging from cystadenomas to borderline mucinous tumors and ultimately to mucinous carcinomas2,3 . The ﬁrst documented case of primary retroperitoneal mucinous carcinoma (PRMCa) was reported by Roth and Ehrlich in 19774 . It has been postulated that these tumors could originate from mature teratomas, deriving from primordial germ cells, or from Brenner tumors, which are sometimes associated with Walthald cell rests1,5 . I

FAQs

Why are primary retroperitoneal mucinous carcinomas (PRMCa) difficult to understand?

PRMCa are exceedingly rare, with fewer than 80 documented cases, and molecular profiling is reported only rarely.

What underlying origin is proposed for the presented PRMCa case?

The case suggests the PRMCa originated in a mature cystic teratoma, consistent with theories that PRMCa may develop from teratoma-related sources.

Which mutations were identified and what is their significance?

Molecular analysis found a KRAS mutation and an ERBB3 mutation, described as the first documented ERBB3 mutation in this specific tumor entity.

Sep 23, 2026

Uploaded by Mabel