Ovarian Yolk Sac Tumor

To evaluate the survival outcomes and establish a risk stratification system in patients with ovarian yolk sac tumors (OYST).

The recurrence-free survival (RFS), disease-specific survival (DSS), and prognostic factors were retrospectively evaluated in 151 OYST patients treated in our hospital between 2006 and 2022. A risk stratification system based on the identified prognostic factors was established.

The median follow-up time was 5.1 years, with a 5-year RFS and DSS rate of 75.5% and 91.2%, respectively. FIGO stage III-IV and the interval between treatment and normalization of AFP were two prognostic predictors. Significant differences in RFS and DSS (both P < 0.001) were identified between patients who had normalized AFP ≤ 3 and ≥ 4 cycles of chemotherapy, or among patients who had normalized AFP after ≤2, 3-4, and ≥ 5 cycles of chemotherapy. FIGO stage I - II and stage III-IV were scored as 0 and 2, respectively. AFP normalization ≤2, 3, 4, and ≥ 5 cycles of chemotherapy were scored as 0, 1, 2, and 4, respectively. A total score of 0-1, 2-3, and ≥ 4 were stratified patients into low-risk (96 patients), intermediate-risk (35 patients), and high-risk groups (20 patients), respectively. Patients in three risk stratifications manifested significant differences in both RFS and DSS (P < 0.0001).

This risk stratification system based on tumor stage and the interval between treatment and normalization of AFP may help to guide clinical management by dividing OYST patients into three risk groups.

Li-Fraumeni syndrome (LFS) is a rare autosomal dominant disease with high penetrance caused by a germline variant of TP53 gene. We report the first case of endometrial cancer after yolk sac tumor with LFS.

The presented female patient underwent right adnexectomy at age 23 because of a yolk sac tumor of the ovary. At the age of 27, the patient was diagnosed with endometrial adenocarcinoma, received cytoreductive surgery and chemotherapy. Given that her personal cancer history along with a strong family history of cancer, her father passing away from lung cancer at age 48 and her grandmother dying of ovarian cancer at age 50, the patient was referred for genetic counseling and testing. Genetic screening revealed a heterozygous pathogenic TP53 c.844C > T, p.( R282 W) with NM_000546.5 variant, a class 5 (C5) variant. This is the first reported case of a yolk sac tumor accompanied by subsequent endometrial cancer that is associated with LFS.

We reported a first case of an endometrial cancer after yolk sac tumor patient with a tumor family history of harboring the germline TP53 pathogenic variation which expanded types of tumor that can be presented in patients with LFS. This case highlights the importance of genetic testing for patients with malignant tumors, as well as patients with a family history of malignant tumors. And our case highlights the necessity of screening for gynecologic tumor in LFS patients.

Immature teratomas are a subset of ovarian teratomas, and the pathogenic relationship between mature and immature ovarian teratomas is unclear. Mature ovarian teratomas are parthenogenetic tumors that arise from a single oocyte/ovum, whereas the origin of immature ovarian teratomas has not been extensively investigated. Since parthenogenetic tumors contain only maternal genomes, genome imprinting in these tumors usually follows a maternal pattern. DNA methylation is among the most important mechanisms of genome imprinting. Therefore, we analyzed the methylation profile of imprinted genes by performing methylation-specific multiplex ligation-dependent probe amplification (MS-MLPA) of 25 imprinting control regions (ICRs) in 10 imprinted genes/gene clusters from formalin-fixed, paraffin-embedded samples obtained from 4 immature ovarian teratomas, 8 mature ovarian teratomas, and 4 ovarian yolk sac tumors (YSTs). Both the immature and mature components showed similar methylation levels in each ICR in immature teratomas. Overall, immature ovarian teratomas showed maternal methylation patterns of imprinted genes in concordance with their parthenogenetic origin. However, they also showed aberrant methylation levels in a few imprinted genes, suggesting that genome imprinting in immature teratomas may partially differ from that in mature teratomas. Microscopic foci of YST were seen in one immature teratoma; the YST component also showed a maternal methylation pattern, unlike the pure YSTs that showed irregular patterns. Thus, teratoma-associated YST and pure YST may have different pathogenic mechanisms.