Ovarian Yolk Sac Tumor With High-Grade Serous Carcinoma in a 62-Year-Old Woman

Molecular Evidence for Epithelial Origin of Mixed Ovarian Epithelial-Germ Cell Neoplasms: Report of 2 Cases and Review of Literature

Ovarian germ cell tumors (GCT) account for 2% to 3% of malignant ovarian neoplasms in Western countries and typically occur within the first 2 decades. When presenting later in life, GCTs may be associated with epithelial malignancies. In these circumstances, it has been theorized that these tumors may originate from a somatic, rather than germ cell origin, especially in the postmenopausal setting; however, the true derivation is not fully understood. Our database was searched for primary ovarian GCTs associated with a malignant epithelial component in patients above 35 yr of age, from 2006 to 2021. Two cases were identified and in each case, slides were reviewed and targeted next-generation sequencing was utilized to identify and compare gene mutation variants in morphologically distinct components. Patient A is a 58-yr-old, with choriocarcinoma and minor component of mucinous adenocarcinoma, and patient B is a 43-yr-old, with yolk sac tumor and minor component of endometrioid adenocarcinoma. The morphologically distinct areas in each case showed disparate staining patterns; however, next-generation sequencing demonstrated identical mutation variants within both the germ cell and epithelial components. Variants in CDKN2A , PIK3CA , PIK3R1 , and TP53 were present in patient A's tumor, while patient B's tumor showed CTNNB1 , PIK3R1 , and 2 PTEN variants. These mutational patterns are similar to those seen in pure epithelial counterparts, suggesting somatic derivation of the germ cell component. These rare tumors portend a poor prognosis and understanding their origin has clinical and therapeutic implications.

Somatic yolk sac differentiation in tumors of the gynecologic tract: A report of two cases and review of the literature

•Somatic yolk sac tumor differentiation associated with malignant neoplasms is uncommon and associated with poor outcome.•In the gynecologic tract, somatic yolk sac differentiation most often arises in postmenopausal patients.•Somatic yolk sac differentiation shares driver mutations with and likely differentiates from the corresponding carcinoma.•This is the first report of somatic yolk sac differentiation in the gynecologic tract from a non-epithelial malignancy.

Molecular characterization of uterine and ovarian tumors with mixed epithelial and germ cell features confirms frequent somatic derivation

Ovarian germ cell tumors, including yolk sac tumors, are most commonly diagnosed in children and young women. Most so-called yolk sac tumors reported in women >35 years old have been associated with an epithelial proliferation (endometriosis or carcinoma). Here, we describe eight cases clinically diagnosed as uterine or ovarian germ cell tumors in women >35 years old. In addition to routine morphologic examination and immunohistochemical evaluation, we present data from targeted next-generation sequencing (NGS) and isochromosome (12p) fluorescence in situ hybridization (FISH). We identified two groups of tumors with mixed germ cell and epithelial features: (1) tumors with background endometriosis and endometrioid carcinoma-like mutations (PTEN, PIK3CA, FGFR2, and CTNNB1), and (2) high-grade morphology, presumptive presence of isochromosome (12p) by FISH, and TP53 or PIK3CA mutations. These findings support the notion that the "germ cell tumor" component of these tumors is often somatically derived. Two tumors in our cohort were from premenopausal women; one showed no detectable mutations by NGS (suggestive of germ cell derivation), whereas the other showed PIK3CA, PTEN, and CTNNB1 mutations (suggestive of somatic derivation). Accurate classification of these tumors is likely important for selection of appropriate chemotherapy.

Ovarian yolk sac tumor in postmenopausal females: A case series and a literature review

RATIONALE

Ovarian yolk sac tumors (YSTs) are the second most common histologic type of ovarian germ cell tumors. Most patients are adolescent and young women, while cases in postmenopausal women were rarely reported. Due to its rarity, we know little about the treatment and prognosis of postmenopausal patients with ovarian YSTs. We reported 3 cases of mixed ovarian YST in postmenopausal females reviewed the related current English literature.

PATIENT CONCERNS

The ages of the three patients were 61, 58 and 77 respectively. The three patients came to the hospital because of the abdominal discomfort or tenderness, and the third patient also has vaginal bleeding.

DIAGNOSES

Imaging examination revealed pelvic mass with cystic and solid components. The elevated serum AFP level and pathologcial examination confirmed mixed ovarian YST.

INTERVENTIONS

All patients received surgery and chemotherapy. Two patients received PEB (cisplatin, etoposide, and bleomycin) chemotherapy initially and one patient received TC (paclitaxel carboplatin) chemotherapy.

OUTCOMES

One patient relapsed 8 months after diagnosis and underwent re-cytoreductive surgery. The three patients all survived at last follow-up.

LESSONS

The diagnosis of postmenopausal ovarian YST is relatively difficult and it can coexist with other germ cell or epithelial tumors. Postmenopausal ovarian YSTs are aggressive, and may have a worse prognosis compared with those in young patients. More aggressive treatment is needed. When YST mixed with epithelial cancer components, adjuvant chemotherapy regimen should include platinum-based chemotherapy aiming at both epithelial ovarian cancer and germ cell tumors.