Choriocarcinoma arising in a serous carcinoma of ovary: an example of histopathology driving treatment

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.

Germ Cell Tumors of the Ovary: A Review

Ovarian germ cell tumors are a diverse group of benign and malignant neoplasms that occur in a wide age range, but with a predilection for younger age group. The majority are represented by the frequently encountered mature cystic teratomas. Malignant germ cell tumors are uncommon, and in some cases have a characteristic clinical presentation. However, from a histologic standpoint these tumors can sometimes be challenging to diagnose due to overlapping morphology with epithelial, and in some cases sex cord tumors. In these cases, a panel of immunohistochemical stains often facilitates the correct diagnosis. This review article discusses the clinicopathologic findings and pertinent ancillary studies of both common and uncommon germ cell tumors of the ovary.

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.

Clinicopathological factors and prognosis analysis of 39 cases of non-gestational ovarian choriocarcinoma

PURPOSE

Non-gestational ovarian choriocarcinoma (NGOC) is a rare malignant germ cell tumor. Through literature review and cases collection, we aim to analyze prognostic factors for NGOC and summarize its clinicopathological characteristics to guide the individualized treatment.

METHODS

We searched PubMed database, Cochrane library, and Google Scholar for cases published between January 1, 1967 and July 31, 2018 using various search terms. We retrieved patients' clinicopathological characteristics, treatment, and prognosis information from included studies. These patients were divided into two groups: died (case group) or alive (control group) group. We summarized and compared their clinical (age, symptoms, R0 resection, serum HCG levels, chemotherapy regimen) and pathological (pure vs non-pure type, tumor size, tumor location, metastasis sites, stage) features by statistical analysis.

RESULTS

Only 39 patients were retrieved from 36 studies in total. The median age was 30 years (range 12- to 65-years old). The peak incidence was in the adolescent age 12-25 years. Median follow-up was 20.3 months (range 1-84 months). 9 (23%) patients died; 24 (62%) patients were alive; 6 (15%) were lost to follow-up. Upon univariate analysis, we found age had a poor impact on overall survival (OS) in NGOC, HR - 0.057, 95% CI - 0.111 to - 0.004. Pure type NGOC has a better OS than mixed type, HR - 2.621, 95% CI - 4.577 to - 0.666. R0 resection is a good prognostic factor for OS, HR 2.967, 95% CI 0.709-5.224.

CONCLUSION

Clinicians should try to achieve R0 resection to improve the prognosis for NGOC patients even among advanced patients.

Germ Cell Tumors of the Female Genital Tract

Ovarian germ cell tumors are a histologically diverse group of neoplasms with a common origin in the primitive germ cell. The vast majority are represented by mature cystic teratoma. In the minority are malignant germ cell tumors including immature teratoma, dysgerminoma, yolk sac tumor, embryonal cell carcinoma, and choriocarcinoma. This article reviews the histologic and immunohistochemical features of the most common ovarian germ cell tumors. The differential diagnoses for each are discussed.

Clear Cell Carcinoma of the Cervix With Choriocarcinomatous Differentiation: Report of an Extremely Rare Phenomenon Associated With Mismatch Repair Protein Abnormality

The presence of trophoblastic differentiation or nongestational choriocarcinoma in a carcinoma is rare but has been described in various organs, including in the female genital tract. We report a cervical clear cell carcinoma admixed with a component of choriocarcinoma in a 52-year-old woman, only the second report of this combination in the literature. Immunohistochemically, the tumor exhibited isolated loss of staining with the mismatch repair protein MSH6. We review the literature on trophoblastic differentiation in cervical carcinoma.

Double Pathology: Malignant Epithelial Ovarian Tumor and Germ Cell Tumor (Choriocarcinoma), a Rare Coexistence

Surface epithelial stromal tumors account for approximately 60% of all ovarian tumors and approximately 90% of all ovarian malignancies. Sex cord stromal tumors account for 7% of all malignant ovarian tumors. Germ cell tumors make up only 3-7% of malignant ovarian tumors. A combination of serous carcinoma of the ovary and choriocarcinoma is rare. Until today such combination has been documented only in six cases in the English literature. Here, we describe a case of ovarian serous carcinoma, where histopathology revealed a combination of serous carcinoma with adjacent choriocarcinoma component in the extraovarian peritoneal deposits. A 64-year-old post-menopausal female was diagnosed to have stage IV ovarian cancer. She received six cycles chemotherapy. Subsequently she underwent optimal cytoreductive surgery. Microscopically, monomorphic histology (serous carcinoma) was noted in both the ovaries and dimorphic histologies (serous carcinoma and choriocarcinoma) in the sigmoid mesocolon nodule, omentum and left subdiaphragmatic nodules. Metronomic chemotherapy continued and patient is on regular follow-up for the past 1 year with stable disease. Recognition of choriocarcinomatous components in ovarian carcinomas is important because of its association with aggressive behavior. In spite of the aggressive histology, the patient is surviving for the past 1 year. Different chemotherapeutic regimens have been used in cases of mixed choriocarcinoma and carcinoma, but established chemotherapeutic regimens have not been described. Chemotherapeutic regimens that target both components have been advocated and used. The absence of choriocarcinoma in ovarian primary and its presence in the extraovarian peritoneal deposits have not been described in the English literature so far. This case is being presented for its rarity.