Ovarian yolk sac tumor arising from an endometrioid carcinoma

Prognostic factors of 87 ovarian yolk sac tumor (OYST) patients and molecular characteristics of persistent and recurrent OYST

OBJECTIVE

We aimed to explore the characteristics of OYST, particularly for persistent and recurrent OYST, in order to explore potential treatment options and thereby improve patient outcomes.

METHODS

We retrospectively reviewed the clinical records of all patients with OYST at Fudan university Shanghai Cancer Center from December 3, 2005 to November 27, 2020. Furthermore, and performed whole-exome sequencing on 17 paired OYST (including 8 paired persistent and recurrent OYST) tumor and blood samples to elucidate the aberrant molecular features.

RESULTS

Totally, 87 OYST patients were included between 2007/03/13 and 2020/11/17. With a median follow-up of 73 [3-189] months, 22 patients relapsed or disease persisted. Overall, 17 patients died with a median overall survival of 21 [3-54] months. Univariate and multivariate analysis revealed tumor histology and residual lesions were independently associated with event free survival and overall survival, cycles to AFP normalization were another independent risk factor for overall survival. For the 8 persistent and recurrent OYST: cancer driver genes including ANKRD36, ANKRD62, DNAH8, MUC5B, NUP205, RYR2, STARD9, MUC16, TTN, ARID1A and PIK3CA were frequently mutated; cell cycle, ABC transporters, HR, NHEJ and AMPK signal pathway demonstrated as the most significantly enriched pathways; TMB, DNA MMR gene mutation and MSI were significantly higher. Mutation signature 11, 19 and 30 were the dominant contributors in persistent and recurrent OYST mutation.

CONCLUSION

Persistent and recurrent OYST associated with poor prognosis, and probably susceptible to immune checkpoint blockade therapy. Molecular characteristics contributed to predict the persistence and recurrence of OYST.

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.

Endometrial, Ovarian, and Peritoneal Involvement by Endometrioid Carcinoma, Yolk Sac Tumor, and Endometriosis: Molecular Evidence for a Shared Precursor

Recent studies have provided molecular confirmation that a subset of yolk sac tumors is somatically derived. Somatically derived yolk sac tumors are typically diagnosed in older women and are often seen adjacent to epithelial proliferations (such as endometriosis or endometrioid carcinoma) with which they share mutations. Here, we present a case of a postmenopausal woman with a yolk sac tumor and endometriosis in the right ovary, endometriosis with glandular crowding and reactive changes in the left ovary, endometrial endometrioid carcinoma, and yolk sac tumor involving the serosa of the colon. Targeted next-generation sequencing of these five tumor components demonstrated identical mutations in PTEN (p.R130G), PIK3CA (p.G1049S), FGFR2 (p.S252W), and FBXW7 (p.R689Q), suggesting that all components arose from a common precursor. The endometrial endometrioid carcinoma harbored additional exclusive mutations involving PIK3CA (p.H1048R) and CTNNB1 (p.S37F).

Neuroblastoma Arising in an Immature Teratoma of the Ovary in a 13-Year-Old

Somatic malignancies arising in mature teratomas are exceedingly rare entities and even more so are those arising in immature teratomas. Here, we present a unique case of a 13-year-old who initially underwent ovarian sparing cystectomy for a 7.7 cm left ovarian mass with a pre-operative diagnosis of mature cystic teratoma. Histologically, all 3 germ cell layers were present and immature neuroepithelial tubules were also identified. Subsequent sections revealed a nodular lesion composed of neuropil, neuroblasts with a spectrum of maturation, and Schwannian-type stroma. The neuroblasts were diffusely positive for PHOX2B. Neuroblastoma arising in an immature teratoma has only been described in the literature once previously in an adult patient.

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.

Two Concurrent Cancers in a 19-Year-Old Patient: Yolk Sac Ovarian Tumor and Metastatic Gastrointestinal Tract Malignancy-Case Report

BACKGROUND

Two concurrent malignancies present in a young person is an extremely rare condition. Diagnoses of gastric cancer primarily concern older patients. There are very few reports of concomitant Krukenberg tumor and germ-cell ovarian malignancy.

CASE

A 19-year-old girl was admitted to the gynecologic oncology department with symptoms of advanced malignancy. Radiological imaging revealed disseminated neoplastic disease with bulky adnexal tumors. Cytoreductive surgery was performed, achieving no visible disease (T = 0 cm). The final pathology report confirmed metastatic mixed adenoneuroendocrine carcinoma (MANEC) in both ovaries, originating from the gastrointestinal tract. Moreover, the primary germ cell yolk sac tumor was found in the left ovary.

CONCLUSION

In cases of concomitant gastric and ovarian tumors, metastatic disease (Krukenberg tumor) should be considered in the differential diagnosis. This concerns even adolescent patients. In particular cases, including tumors with germ cell components, primary debulking surgery is crucial for prognosis.

Pure primary yolk sac tumor of the endometrium tends to occur at a younger age: A case report and literature analysis

We present a case of primary yolk sac tumor of the endometrium. This rare tumor occurred in a 43-year-old woman with a pure primary yolk sac tumor. The tumor resembled yolk sac tumor morphology of the ovary. Tumor cells expressed SALL4, AFP, GPC-3, and AE1/AE3 and were focal positive for PAX8. EMA, ER, and PR, among others, were negative. We further analyzed 29 reported cases of this rare tumor in the literature. In total, 17 of 30 patients (57%) had pure endometrial yolk sac tumor, and 13 (43%) had a concomitant somatic neoplasm (endometrial adenocarcinoma was the most common). Although the average age was 52 years (range: 24–87 years), patients with pure yolk sac tumor were younger than those with concomitant somatic tumors, with a mean age of 44.41 years (24–68 years) versus 61.92 years (28–87 years), P = 0.008. Patients with endometrial yolk sac tumor combined with somatic tumor tend to have a slightly higher stage and a poor prognosis.

Alpha-fetoprotein (AFP)-producing epithelial ovarian carcinoma (EOC): a retrospective study of 27 cases

Objective

The aim of the study was to investigate the relative risk factors associated with the prognosis and effective treatments of alpha-fetoprotein (AFP)-producing epithelial ovarian carcinoma (EOC).

Method

We presented three cases of AFP-producing EOC and performed a brief review to summarize the clinicopathological features and prognostic factors of 24 cases that have been previously reported. We evaluated the correlations among prognostic and clinical parameters, such as stage, pathology and chemotherapy regimens. In addition, a retrospective review of these 27 cases was conducted, and survival curves were estimated using the Kaplan–Meier method.

Results

The patients were aged between 23 and 77 years. The median overall survival was 10 months, and ten (37.04%) patients died within 18 months. We compared the overall mean survival times of all patients in different stages, and the results suggest that the postoperative pathological staging is hardly correlated with prognosis (P = 0.76). There was a correlation between pathology and prognosis (P = 0.0018). The mean survival time was longer for patients who had undergone chemotherapy than for those without chemotherapy (14.88 vs 0.65 months) (P < 0.0001). Moreover, although patients had a good response to the regimens for PEB and TC (P = 0.004), there was no significant difference between PEB and TC (P = 0.386).

Conclusions

AFP-producing EOC is uncommon and regarded as an extremely malignant type of tumor. Patients with chemotherapy may have a longer survival time; additionally, PEB and TC may be an optimal selection for this kind of tumor. Further large-scale studies are needed to confirm our findings.

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.

Pathology of Endometrioid and Clear Cell Carcinoma of the Ovary

This review is an appraisal of the current state of knowledge of 2 enigmatic histotypes of ovarian carcinoma: endometrioid and clear cell carcinoma. Both show an association endometriosis and the hereditary nonpolyposis colorectal cancer (Lynch) syndrome, and both typically present at an early stage. Pathologic and immunohistochemical features that distinguish these tumors from high-grade serous carcinomas, each other, and other potential mimics are discussed, as are staging, grading, and molecular pathogenesis.

Endometrial tumors with yolk sac tumor-like morphologic patterns or immunophenotypes: an expanded appraisal

Uterine yolk sac tumors have gained increased recognition in recent years. The current study is a multi-faceted examination of yolk sac tumor-like phenotypes in endometrial tumors, based on an analysis of 3 groups of uterine tumors: Group 1: 9 endometrial tumors that had been classified as yolk sac tumor, or as having a yolk sac tumor component, were assessed with a 35-marker immunohistochemical panel, with the goal of defining their immunophenotypic spectrum; Group 2, comprised of 70 endometrial carcinomas of various histotypes, were analyzed for their expression of SALL4, Glypican-3, and AFP, to assess the specificity of these markers for yolk sac tumors relative to endometrial carcinomas; Group 3, comprised of 626 archived cases of endometrial carcinoma/carcinosarcoma, reviewed to define the frequency of yolk sac tumor-like morphology therein. Yolk sac tumor areas in the Group 1 cases were consistently immunoreactive for SALL4 and Glypican-3; variably positive for AFP (89%), Villin (89%), PLAP (78%), 34βE12 (67%), CAM 5.2 (62.5%), EMA (56%), CD117 (50%), p16 (50%), CDX2 (44%), p53 (44% aberrant), MOC31 (37.5%), CK7 (33%), GATA3 (33%), CK5 (25%), and PAX8 (11%); and were negative for CD30, Napsin A, OCT4, estrogen, androgen, and progesterone receptors. 29 (41%) of the 70 group-2 cases expressed at least one of the 3 markers, and 96% of the positive cases was a high-grade histotype. Glypican-3, SALL4, and AFP were positive in 30, 20, and 2.8% of group-2 cases respectively; however, co-expression of any 2, or all 3 markers was uncommon (<9 and 1.4% of cases respectively). Potential yolk sac tumor-like morphology was identified in 5 (0.8%) of 626 group-3 cases, and three were ultimately deemed to be true yolk sac tumor phenotypes based on their morphologic and immunophenotypic similarity to the group 1 cases. These findings highlight the broad immunophenotypic spectrum of uterine yolk sac tumors, the potential pitfalls associated with using immunophenotypes alone to define yolk sac tumor differentiation in endometrial carcinoma, and the utility and limitations of morphologic assessment to identify yolk sac tumors at this site.

A case of ovarian endometrioid adenocarcinoma with yolk sac differentiation and Lynch syndrome

Ovarian endometrioid adenocarcinoma with yolk sac component has been reported in fewer than twenty cases in the literature. A majority of the diagnoses are described in postmenopausal women without specific reference to germline genetic testing. We describe, to our knowledge, the first case in the English literature of a premenopausal woman that presented with an ovarian endometrioid adenocarcinoma with focal yolk sac component and was subsequently found to have a germline MSH2 mutation confirming a diagnosis of Lynch syndrome. Concurrent diagnosis of ovarian endometrioid adenocarcinoma with yolk sac tumor and Lynch syndrome is an extremely rare finding in a young patient and requires careful follow-up. Genetics evaluation and testing may be reasonable for individuals with this rare or mixed tumor pathology at young age of onset and can have clinical utility in guiding future cancer treatment or surveillance.

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.

Germ cell tumour growth patterns originating from clear cell carcinomas of the ovary and endometrium: a comparative immunohistochemical study favouring their origin from somatic stem cells

AIMS

To report a series of 11 ovarian and one endometrial neoplasm in elderly patients with mixed clear cell tumour and germ cell tumour (GCT) components, to compare their immunohistochemical profiles and demonstrate a putative stem cell population.

METHODS AND RESULTS

The clear cell tumours included 11 clear cell carcinomas (CCC) and one borderline clear cell tumour, while the GCT always included glandular yolk sac tumour (YST). In four cases, there were also foci of teratoma with immature neuroepithelial and endodermal tissues and undifferentiated areas showing true embryoids. To distinguish between the clear cell and YST components, the following antibodies were used: HNF1-β, napsin-A, cytokeratin 7 (CK7), PAX8, EMA, AFP, SALL4, villin, glypican-3 (GPC-3), GATA3, HepPar-1, OCT4, CDX2, CD30 and SOX2. HNF1-β, CK7, EMA and GPC-3 were often expressed in both components. Other markers had higher specificity for each cellular lineage; napsin-A and PAX8 were expressed only in CCC, while SALL4, villin, AFP and HepPar-1 were positive in the glandular YST component but negative in the clear cell component. OCT4 expression occurred in six of 10 cases and consistently in teratoma (four of four).

CONCLUSIONS

There is considerable immunophenotypical overlap between the two components in these mixed neoplasms, and a panel of markers should be used to facilitate the distinction. We propose that OCT4-expressing somatic cancer cells differentiate into GCT and represent spontaneously induced pluripotent stem cells, possibly conditioned by age-related epigenetic factors. These neoplasms have features of prepubertal type GCT showing lack of 12p gain, preponderance of YST and coexistence with immature neuroectoderm. However, there may also be undifferentiated stem cell areas with embryoid bodies, of the type seen in postpubertal testicular GCT, but lacking a complete embryonal carcinoma immunophenotype.

Endometriosis-associated ovarian neoplasia

This article reviews the most relevant pathological and molecular features of ovarian tumours that are associated with endometriosis. Endometriosis is a common condition, affecting 5-15% of all women, and it has been estimated that 0.5-1% of cases are complicated by neoplasia. The most common malignant tumours in this setting are endometrioid adenocarcinoma and clear cell adenocarcinoma, each accounting for approximately 10% of ovarian carcinomas in Western countries. A minority of cases are associated with Lynch syndrome. These carcinomas are often confined to the ovaries at presentation in which case they have relatively favourable outcomes. However, high-stage tumours, particularly clear cell carcinomas, generally have a poor prognosis and this partly reflects relative resistance to current treatment. Histological diagnosis is straightforward in the majority of cases but some variants, for example endometrioid carcinomas with sex cord-like appearances or oxyphil cells, may create diagnostic difficulty. Similarly, clear cell carcinomas can show a range of architectural and cytological patterns that overlap with other tumours, both primary and metastatic, involving the ovaries. Endometriosis-associated borderline tumours are less common, and they often show mixed patterns of differentiation (seromucinous tumours). Atypical endometriosis may represent an intermediate step in neoplastic progression and some of these lesions demonstrate immunohistological and molecular alterations similar to those observed in endometriosis-related tumours. ARID1A mutations are relatively common in all of these tumours, but each has additional characteristic molecular alterations which are likely to be of increasing clinical relevance as targeted therapies are developed. Less is known of the pathogenesis of rarer endometriosis-associated ovarian tumours including endometrioid stromal sarcoma, mesodermal (Müllerian) adenosarcoma, and carcinosarcoma. This article also briefly reviews the issue of synchronous endometrioid carcinomas of the endometrium and the ovary, including the most recent developments on pathogenesis.

Ovarian yolk sac tumor coexisting with epithelial ovarian cancer: An aggressive rare entity

Yolk sac tumor (YST) is the second most common subtype of ovarian germ cell tumors. It usually occurs in the second and third decades of life and is rare in postmenopausal women. In postmenopausal women, YST is commonly an aggressive tumor and can present as a pure germ cell component or as a mixed component with other germ cell or epithelial components. The recognition of this histological subtype is important not only for differential diagnosis but also for determining prognosis and treatment decisions. In this case report, we describe a 61-year-old woman with YST coexisting with epithelial carcinoma focusing on the efficacy of systemic therapies.

High-level expression of divergent endodermal lineage markers in gonadal and extra-gonadal yolk sac tumors

Yolk sac tumors occur at both gonadal and extra-gonadal sites. A recent case of ovarian endometrioid-pattern yolk sac tumor with strong diffuse expression of TTF-1 illustrated the potential for misdiagnosis due to divergent expression of endodermal lineage markers. The aim of this study was to investigate the expression of four divergent endodermal lineage markers, TTF-1, CDX2, Hep Par 1, and Napsin A, in gonadal and extra-gonadal yolk sac tumors of differing age, sex, and location (excluding foci of overt hepatoid differentiation). We identified 26 cases (5 ovarian, 15 testicular, and 6 extra-gonadal) containing yolk sac tumor as identified by typical histology and confirmed by positive immunohistochemical staining for alpha-fetoprotein and glypican-3. Mixed or ambiguous foci were confirmed by immunohistochemistry (SALL4 positive and Oct-4 negative). The relative proportion of three histologic patterns: reticular/cystic, solid/myxoid, and glandular was estimated. Percent positivity for the four divergent endodermal lineage markers was compared within yolk sac tumor areas according to site, age group, and histologic pattern. High-level (>25%) staining for one or more divergent endodermal lineage markers was seen in eleven cases: Hep Par 1 in seven cases, all post-pubertal, TTF-1 in four cases, two ovarian and two extra-gonadal, and CDX2 in three cases, with no age or site predilection. No case highly expressed all three divergent endodermal lineage markers, but four co-expressed high levels of two markers: two ovarian yolk sac tumors with TTF-1 and Hep Par 1, one testicular yolk sac tumor with CDX2 and Hep Par 1, and one extra-gonadal yolk sac tumors with TTF-1 and CDX2. While no absolute correlation of high-level divergent endodermal lineage marker expression with histologic subtype was observed, TTF-1 and CDX2 expression was predominantly seen in reticular/cystic and glandular areas while Hep Par 1 was most frequent in myxoid/solid and glandular areas.

Yolk sac tumours of the female genital tract in older adults derive commonly from somatic epithelial neoplasms: somatically derived yolk sac tumours

AIMS

To report 18 yolk sac tumours (YSTs) of the female genital tract (17 ovary, one uterus) in patients aged 40 years or over, most arising from a somatic epithelial neoplasm.

METHODS AND RESULTS

Six patients had pure YST, two were associated with immature teratoma (one with an endometrioid adenocarcinoma) and in 11 there was an epithelial neoplasm comprising high-grade serous carcinoma (HGSC) (n = 5), clear cell carcinoma (n = 1), borderline clear cell adenofibroma (n = 1), endometrioid adenocarcinoma (n = 2), serous tubal intra-epithelial carcinoma (n = 1) and large-cell neuroendocrine carcinoma (n = 1). In one case of pure YST, there was an ipsilateral endometriotic cyst but no other neoplastic component. In two cases, the YST was a hepatoid variant and in most of the others it exhibited predominantly glandular morphology, closely mimicking an epithelial neoplasm.

CONCLUSIONS

Pathologists should be aware of the association between YST and an epithelial neoplasm, the former probably arising from the latter through a process of neometaplasia/retrodifferentiation. Those rare gynaecological pure glandular YSTs in adults may arise secondary to total overgrowth of an epithelial neoplasm. Pathologists need a high index of suspicion to diagnose the YST component, as the morphology is characteristically of a glandular variant with marked morphological overlap with adenocarcinomas. There is also often significant immunophenotypical overlap with epithelial neoplasms, as the YST component may be positive with epithelial membrane antigen (EMA), BerEP4 and cytokeratin 7 (CK7), as well as YST markers. We propose the term 'somatically derived YSTs' for these neoplasms and suggest unification of the terminology between different sites where such neoplasms occur.

Post-menopausal presentation of yolk sac germ cell tumour

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Yolk sac germ cell tumours are rare in post-menopausal patients.

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Most involve mixed yolk sac tumours

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Consider diagnosis in patients with a pelvic–abdominal mass and raised AFP

Germ cell tumors of the ovary: an update

CONTEXT

The field of ovarian germ cell tumors (OGCTs) has remained relatively unchanged in the last 2 decades. However, the introduction of new stem cell pluripotency markers has provided a new understanding into the identification and taxonomy of OGCT types. New data have provided new insights into unusual teratoma-associated autoimmune disorders and the origin of gliomatosis peritonei.

OBJECTIVE

To review the impact of new pluripotency markers in the diagnosis of malignant OGCT (MOGCT) and analyze new nomenclature proposals and clinicopathologic entities.

DATA SOURCES

Ovarian germ cell tumors from routine material and expert consultation files at San Cecilio University Hospital, Granada, Spain, and the relevant literature were reviewed.

CONCLUSIONS

Although a correct diagnosis of MOGCT can often be made with histologic and classic immunohistochemical studies, the new immunohistochemical pluripotency markers give higher diagnostic accuracy. Germ cell tumors represent a caricature of the phases of normal embryonic differentiation from primordial germ and stem cells to extraembryonal and somatic tissue differentiation. Since every stage of differentiation and its related tumor type exhibit characteristic markers, the analysis of their expression facilitates tumor typing, thus complementing the use of classic antibodies. They also allow a more precise evaluation of the degree of immaturity in teratoma. The new term, primitive endodermal tumors, simplifies the understanding of the complex histology of the yolk sac tumor group, as this terminology encompasses its multiple endodermal differentiations. Recently described autoimmune encephalitis due to antibodies against the N-methyl-d-aspartate receptor has become the most frequent autoimmune disorder associated with ovarian teratoma.

Hepatoid carcinoma of the ovary: A case report and review of the literature

Hepatoid carcinoma of the ovary is a type of tumor resembling hepatocellular carcinoma that arises from the ovary. Hepatoid carcinoma patients are predominantly elderly females ranging between 35 and 78 years of age, with an average age of 56 years. It was suggested that, microscopically, bile canalicular structures are rare, but among nine cases examined for bile canalicular structures, four demonstrated a positive result. Here, we report a case of a 55-year-old female who presented to the Second Xiangya Hospital, Changsha, China, with lower abdominal pain, abdominal distention and increasing abdominal girth. The patient underwent total hysterectomy, bilateral salpingo-oophorectomy, omentectomy, tumor debulking and postoperative chemotherapy. A mass in the left ovary measuring approximately 11 cm in diameter was identified. Microscopic and immunohistochemical results suggested that it was a hepatoid carcinoma of the left ovary.

RNA-binding protein LIN28 is a sensitive marker of ovarian primitive germ cell tumours

AIMS

LIN28 is an RNA-binding protein that has been detected in testicular germ cell tumours (GCTs), but its status in ovarian GCTs is unknown. The aim was to determine the immunohistochemical profile of LIN28 in ovarian GCTs.

METHODS AND RESULTS

Immunohistochemistry of LIN28 was performed in 110 primary and 11 metastatic ovarian GCTs. The percentage of tumour cells stained was scored as 0, 1+ (1-30% cells), 2+ (31-60%), 3+ (61-90%), and 4+ (>90%). To determine its specificity, we stained LIN28 in 119 non-GCTs, including 37 clear cell carcinomas. Strong 4+ LIN28 staining was seen in 4/4 (100%) gonadoblastomas, 7/7 (100%) embryonal carcinomas (ECs), and 41/41 (100%) yolk sac tumours (YSTs). Among 39 dysgerminomas, 4+ staining was seen in 37 and 3+ staining in two (strong in 37; mixed weak and strong in two). Twelve of 14 immature teratomas showed variable LIN28 staining (1+ to 4+) in the immature neuroepithelium (weak to strong staining), whereas mature teratomas, carcinoids, struma ovarii and strumal carcinoids were negative. Only 5/117 non-GCTs (1/37 clear cell carcinomas) showed weak to moderate 1-2+ staining.

CONCLUSIONS

LIN28 is a sensitive marker for gonadoblastomas, dysgerminomas, ECs, and YSTs. LIN28 can be used to distinguish them from non-GCTs.

SALL4 is a novel sensitive and specific marker of ovarian primitive germ cell tumors and is particularly useful in distinguishing yolk sac tumor from clear cell carcinoma

Ovarian primitive germ cell tumors (GCTs) are uncommon tumors and sometimes pose diagnostic challenges. Among them, yolk sac tumor (YST) poses the greatest diagnostic difficulty and can be mistaken for clear cell carcinoma (CCC). Current immunohistochemical markers such as alpha-fetoprotein (AFP), glypican-3, cytokeratin (CK) 7, and epithelial membrane antigen (EMA) used to distinguish YST from CCC lack adequate sensitivity and specificity. Here by immunohistochemistry, we investigated a novel marker SALL4 in 98 GCTs (29 YSTs, 18 dysgerminomas, 6 gonadoblastomas, 6 embryonal carcinomas, 15 immature and 12 mature teratomas, 7 carcinoid tumors, 3 strumal carcinoids, and 2 struma ovarii) with particular interest of exploring SALL4 to distinguish YST from CCC. One hundred sixty-three non-GCTs including 45 CCCs were also stained. We found that SALL4 is strongly positive in more than 90% tumor cells in all YSTs, dysgerminomas, gonadoblastomas, and embryonal carcinomas. Variable SALL4 staining is seen in 11 of 15 immature teratomas. All other GCTs included in this study are negative for SALL4. Except 3 CCCs with focal SALL4 staining (<15% tumor cells), SALL4 is negative in the remaining 160 non-GCTs. We also compared SALL4 with AFP, glypican-3, CK7, and EMA in all YSTs and CCCs. AFP and glypican-3 are positive in 24 (83%) and 20 (69%) YSTs, respectively, whereas 16 (35%) and 13(28%) CCCs show positive AFP and glypican-3 staining, respectively. Three (10%) and 4 (14%) YSTs show focal (<2% tumor cells) CK7 and EMA staining, respectively. CK7 and EMA are positive in all 45 CCCs but 3 (7%) and 1 (2%) cases show staining in less than 30% tumor cells, respectively. Our findings indicate that SALL4 is a novel sensitive and specific marker for ovarian primitive GCTs. SALL4 is particularly useful in distinguishing YST from CCC and better than AFP, glypican-3, CK7, and EMA.

Yolk sac tumours of the ovary: evaluation of clinicopathological features and prognostic factors

OBJECTIVE

To evaluate the clinicopathological prognostic features, factors and outcomes of chemotherapy in ovarian yolk sac tumours (YST).

STUDY DESIGN

We reviewed the medical records of 32 women with ovarian YST treated from 1990 to 2006 at two centres.

RESULTS

The median follow-up was 36 months. The median age was 22 (range, 9-68). Two patients were postmenopausal. The most common symptoms at diagnosis included abdominal swelling or mass (72%) and abdominopelvic pain (62%). The location of the tumour was bilateral in 2 cases. Eight patients were in stage I, 4 patients in stage II, 17 patients in stage III, and 3 patients in stage IV. Eighteen patients underwent unilateral salpingo-oophorectomy, two bilateral salpingo-oophorectomy and two cystectomy, while 10 patients had total abdominal hysterectomy and two bilateral salpingo-oophorectomy. Of 32 patients who received postoperative chemotherapy, 27 were treated with a bleomycin/etoposide/cisplatin (BEP) regimen. Seventy-two percent of patients were alive at the last follow-up visit. Ten (31%) patients suffered from a recurrence of the disease with a median time to recurrence of 8 months (range, 6-28 months). The most common site of recurrence was the intra-abdominal space, with 8 patients. Only one patient who had recurrence could be salvaged. Fertility-sparing surgery was found at least as effective as radical surgery. While age, histology (mixed vs. pure), stage, tumour size, ascites, and marker levels were not found as prognostic factors, the presence of residual tumour (P=0.014) and BEP chemotherapy (P=0.016) were significant prognostic factors in univariate analysis.

CONCLUSIONS

In patients with ovarian YST, fertility-sparing surgery is as effective as radical surgery. Optimal cytoreductive surgery and standard BEP regimen are the most decisive prognostic factors. In these tumours, adjunctive therapeutic modalities to eradicate intra-abdominal disease and effective salvage therapy strategies are needed.

Alpha-fetoprotein (AFP)-producing ovarian tumor in an elderly woman

Apart from typical yolk sac tumors, ovarian tumors with elevated alfa-fetoprotein (AFP) are uncommon and the differential diagnosis needs to consider the hepatoid pattern of a yolk sac tumor, hepatocellular carcinoma metastatic to the ovary, hepatoid carcinoma, and other epithelial ovarian tumors. We report here an AFP-producing ovarian tumor with uncertain pathological diagnosis, which was extremely responsive to chemotherapy. A 59-year-old Japanese woman presented with lower abdominal distension and was found to have a left ovarian mass on pelvic examination and magnetic resonance imaging (MRI) scan. Laboratory tests showed serum AFP, 73 687 ng/ml; carbohydrate antigen 125 (CA125), 1599 U/ml; and carcinoembryonic antigen (CEA), 13.9 ng/ml. Total hysterectomy with bilateral salpingo-oophorectomy, partial omentectomy, and low anterior resection of the rectum was performed, without any residual macroscopic tumor. Microscopically, the tumor was characterized by a hepatoid carcinomatous component composed of solid sheets of large eosinophilic cells with pleomorphic nuclei. The pathological stage was pT2N0M0. Tumor cells were diffusely immunoreactive for AFP and cytokeratin (CAM5.2), but monoclonal CEA and CA19-9 were focally positive in the cytoplasm, while CA125 was negative. The patient was treated postoperatively with three cycles of chemotherapy consisting of bleomycin, etoposide, and cisplatin; with this regimen, serum AFP decreased to 16 ng/ml from 12 600 ng/ml just before the initiation of chemotherapy. The patient received secondary cytoreductive surgery of systemic lymphadenectomy, which revealed no evidence of residual tumor.

A case of ovarian endometrioid adenocarcinoma with a yolk sac tumor component

Endometrioid adenocarcinoma of the ovary coexists very rarely with yolk sac tumor (YST). This unusual mixed tumor is thought to be a rare variant of endometrioid ovarian carcinoma because of its aggressive behavior, lack of response to chemotherapy, and unfavorable prognosis. We report a case of ovarian endometrioid adenocarcinoma with a YST component in a postmenopausal woman. The patient was treated by surgery and a combination of bleomycin, etoposide, and cisplatin and taxol and carboplatin. She has been clinically free of tumor for 20 months. Immunohistochemically, the YST component reacted for alpha-fetoprotein. YST areas were negative for both CA125 and sex-hormone receptors. Cytokeratin7 and epithelial membrane antigen were negative in YST, but positive in endometrioid adenocarcinoma. The occurrence of this unusual case suggests that even somatic carcinomas may acquire an extraembryonal germ cell differentiation.

Malignant ovarian tumor composed of endometrioid adenocarcinoma, clear cell adenocarcinoma, squamous cell carcinoma, yolk sac tumor and immature teratoma with prominent neuroectodermal and rhabdomyosarcomatous differentiation: a case study

BACKGROUND

Cases of malignant ovarian tumor composed of müllerian-type epithelial tumor and malignant germ cell tumor are extremely rare.

CASE

We herein report the case of a 34-year-old woman with an ovarian tumor which was composed of endometrioid adenocarcinoma (EAC), clear cell adenocarcinoma (CCC), squamous cell carcinoma, yolk sac tumor (YST) and immature teratoma with prominent neuroectodermal and rhabdomyosarcomatous differentiation. Even after systemic chemotherapy, this intriguing tumor recurred again and again, which is in contrast to pure germ cell tumor which is known to be sensitive to chemotherapy.

CONCLUSION

No previous cases with an identical composition have been found in the literature. Correct diagnosis of this complex and aggressive tumor is paramount.

Primary yolk sac tumor concomitant with carcinosarcoma originating from the endometrium: case report

BACKGROUND

A primary yolk sac tumor (YST) with carcinosarcoma originating from the endometrium is extremely rare, to our knowledge, this is the third documented instance. Several hypotheses exist is to its histogenesis.

CASE

A 65-year-old Japanese woman was diagnosed with a uterine malignancy and underwent surgical treatment and chemotherapy. The postoperative diagnosis was primary carcinosarcoma concomitant with a YST of the uterus. Immunohistochemical staining revealed that the tumor area suspected to be a YST was positive for alpha-fetoprotein.

CONCLUSION

We report a case of carcinosarcoma concomitant with a YST of uterus. This case is the third documented instance of a YST with concomitant with carcinosarcoma originating from the endometrium. The histogenesis in this case is suggests aberrantly differentiated somatic cells.

The Use of Cytokeratin 7 and EMA in Differentiating Ovarian Yolk Sac Tumors From Endometrioid and Clear Cell Carcinomas

Yolk sac tumors (YSTs) have a variety of morphologic patterns, some of which can resemble either endometrioid adenocarcinoma (EAC) or clear cell carcinoma (CCC). Immunohistochemical staining for alpha-fetoprotein (AFP) is usually only focal and thus is not always helpful in the diagnosis of YST, and pancytokeratin (CK) is expressed by all three tumors. We studied a battery of immunohistochemical markers with specific attention to the utility of cytokeratin 7 (CK7) in differentiating YST from EAC and CCC. A total of 46 ovarian tumors were retrieved for this study: 16 YST, 19 EAC, and 11 CCC. The three groups were analyzed for the expression of CK7, AFP, Leu-M1 (CD15), EMA, and WT1 by immunohistochemistry. In addition, CK and c-kit (CD117) were studied in the YSTs. All of the YSTs tested (100%) were positive for CK. CK7 was considered negative in all 16 YST cases (100%), although a few tumor cells (1%-2%) stained in 4 cases. In contrast, 17 of 19 EACs and all 11 CCCs had diffuse 3+ to 4+ positivity for CK7; the two other EACs showed 2+ positivity for CK7 (40% and 30% of the tumors). AFP was positive in 12 of 15 YSTs (80%), but was generally focal with 1+ staining in 10 cases (67%); only 2 cases were 3+. All of the EACs and CCCs were negative for AFP. Leu-M1 was 1+ in 9 of 15 YSTs (60%), while the remaining 6 were considered negative. Leu-M1 was positive in 10 of 15 EACs tested (67%), but the staining was variable with 1 case 3+, 3 cases 2+, and 6 cases 1+. In the CCCs, 10 cases (91%) were 3+ to 4+, and 1 case was 1+. EMA was essentially negative in 15 of 15 YSTs (100%), with 3 completely negative and 12 showing very focal (<5%) staining. Eight of 12 EACs showed 4+ staining, 3 showed 3+ staining, and 1 showed 2+ staining. All of the 11 CCCs (100%) showed 4+ staining. WT1 was negative in all cases of YST and CCC; 16 of 18 EAC tested (89%) were negative for WT1, but 2 (11%) were 4+ positive. C-kit was negative in all YSTs. In conclusion, it is important for pathologists to be aware that YSTs may mimic EACs and CCCs and that this distinction is important for the clinical management of patients with these tumors. AFP staining is focal in most YST, so an absence of staining does not exclude this diagnosis. CK7 and EMA are essentially negative in YST but are diffusely positive in CCC and EAC, making them useful markers for differentiating YSTs from both CCCs and EACs. Leu-M1 may also be helpful for distinguishing YSTs from CCCs.

Malignant transformation of atypical endometrial hyperplasia after progesterone therapy showing germ-cell tumor-like differentiation

A 31-year-old woman was treated for atypical endometrial hyperplasia (AEH) with high-dose medroxyprogesterone acetate (MPA) therapy to preserve fertility. The AEH was found by repeated cytologic and histologic examinations to have completely disappeared with the therapy, but 3 years after her last follow up she required emergency surgery to treat severe genital bleeding. The hysterectomied uterus consisted mostly of poorly differentiated adenocarcinoma, G3 endometrioid type. Minor AEH was present in the exophytic area, in which some glands were cystically dilated. Part of the AEH had transformed into other histologic features with germ-cell-like differentiation, demonstrated by immunohistochemical positive reaction of placental alkaline phosphatase, alpha-fetoprotein, and human chorionic gonadotrophin. Recurrent AEH had undergone malignant transformation, resulting in the development of well- and poorly differentiated adenocarcinoma and tumor exhibiting germ-cell-like differentiation. The patient died of a massive tumor extension 7 months after surgery. The AEH before MPA therapy and the recurrent tumors had genetically different characteristics based on evidence of a loss of heterozygosity, detected at D8S1132 (chromosomal locus, 8q22.1) in the latter but not in the former, by analysis of genetic alterations using microsatellite markers.

Ovarian yolk sac tumor associated with endometrioid carcinoma and mucinous cystadenoma of the ovary

The clinicopathologic and immunohistochemical findings of an unusual case of ovarian yolk sac tumor associated with endometrioid carcinoma and mucinous cystadenoma of the ovary are reported. The tumor was detected in a 51-year-old postmenopausal woman who presented with abdominal swelling and a pelvic mass. The patient underwent total abdominal hysterectomy with bilateral salpingo-oophorectomy and omentectomy. The tumor was confined to the right ovary and measured 16.0 cm in greatest dimension. Microscopic examination revealed that the tumor had a yolk sac component associated with an endometrioid carcinoma, grade I, and a mucinous cystadenoma. A background of atypical endometriosis was noted. Immunoperoxidase studies showed that the yolk sac component stained diffusely with a cytokeratin cocktail and was focally positive for alpha-fetoprotein. It was negative for keratin 7. In contrast, the endometrioid carcinoma stained positive for keratin 7 in addition to the cytokeratin cocktail, but was negative for alpha-fetoprotein. After surgery, the patient received three cycles of chemotherapy. However, the disease progressed and the patient died 10 months after the diagnosis of the ovarian tumor.

A case of ovarian endometrioid adenocarcinoma with yolk sac tumor component in a postmenopausal woman

The co-existence of an endometrioid adenocarcinoma with an ovarian yolk sac tumor is very rare. Only eight cases have been reported in the English language literature. A 54-year-old postmenopausal woman with a 6-month history of progressive abdominal distension was seen at our hospital. MR imaging revealed a large cyst with a solid intramural node. Serum alpha-fetoprotein and CA125 levels were 13143 ng/ml and 170 U/ml, respectively. At laparotomy, a large tumor approximately 20 cm in diameter was found to occupy the abdominal cavity, adhering to the swollen appendix and part of the omentum. Microscopically, foci of endometrioid adenocarcinoma together with a yolk sac tumor component were observed within a large endometriotic cyst. Since the tumor was clinically staged 1c, the patient was given 500 mg of intraperitoneal carboplatin postoperatively, followed by five courses of combination chemotherapy consisting of cisplatin, etoposide and peplomycin at 4-week intervals. The levels of both serum alpha-fetoprotein and CA 125 decreased gradually to normal ranges and remained normal at the most recent follow-up on 29 December, 2001. In contrast to a very poor prognosis of this tumor in previously reported cases, our patient showed no sign of recurrence during a 21-month follow-up period.

Ovarian endometrioid-like yolk sac tumor treated by surgery alone, with recurrence at 12 years

We describe the case of a stage Ia endometrioid-like yolk sac tumor (YST) of the ovary, which was originally misdiagnosed as a malignant struma ovarii and not treated with adjuvant chemotherapy. After 12 years, a contralateral dermoid cyst was excised along with a small omental nodule of partially necrotic and calcified endometrioid-like YST. No tumor was detected in several other biopsy specimens, and a peritoneal lavage was negative for tumor cells. Since there was no evidence of remaining tumor and the serum alpha-fetoprotein (AFP) level was normal after the second operation, the patient was followed. Serial serum AFP levels remained normal for 4 months. At a second-look laparotomy after 4 months, a small tumor nodule was removed from the cul-de-sac. Postoperatively, the patient received three cycles of BEP chemotherapy. The long disease-free interval after the first operation in spite of the presence of occult spread to the omentum and to the pouch of Douglas in this case indicates that some endometrioid-like YSTs may have an indolent course. The present case underscores the importance of careful surgical staging and of long-term follow-up in cases of primitive germ cell tumors of the ovary.

Ovarian yolk sac tumor with endometrioid carcinoma arising from endometriosis in a postmenopausal woman, with special reference to expression of alpha-fetoprotein, sex steroid receptors, and p53

A case of a yolk sac tumor (YST) with an ovarian endometrioid adenocarcinoma arising from endometriosis in a postmenopausal woman is described. Clinically, the case showed an aggressive course and did not respond to chemotherapy; the patient died of her disease 6 months after the operation. Histologically, the tumor consisted predominantly of an endometrioid adenocarcinoma, but it also showed microscopic features characteristic of YST. The tumor also contained benign endometriotic lesions with direct transition to the endometrioid adenocarcinoma. Immunohistochemical study revealed that not only the YST, but also the endometrioid adenocarcinoma was partly positive for alpha-fetoprotein. There was an inverse relationship between the endometriosis and the endometrioid adenocarcinoma in terms of the expression of sex steroid receptors and p53: adenocarcinoma cells were positive for p53 but negative for sex steroid receptors, whereas endometriotic epithelial cells were positive for sex steroid receptors but negative for p53.

Primary yolk sac tumor of the endometrium: a case report and review of the literature

A 49-year-old woman was admitted with abnormal vaginal bleeding of 5 months duration. Hysteroscopy showed polypoid formations in the uterine cavity. Biopsy of a polyp revealed an anaplastic malignant tumor. A total hysterectomy with bilateral salpingo-oophorectomy and iliac lymphadenectomy were performed. A polypoid soft white-yellowish tumor originated from the endometrium. The biopsies plus sections of the operative specimen were histologically similar and displayed typical features of yolk sac tumor (YST) with tubulo-papillary pattern. Schiller-Duval bodies and PAS-positive, diastase-resistant, hyaline droplets were present. There was no neoplastic involvement of the cervix, ovaries, and iliac lymph nodes. Tumor cells and hyaline globules were strongly immunoreactive with alpha-fetoprotein antibody. The patient refused chemotherapy and was subsequently treated by external radiotherapy. The patient remained free of disease 28 months after surgery. There are only four additional cases of primary YST of the endometrium reported in literature. On the basis of the small number of cases reported, such tumors appear to have clinical and pathological features similar to their ovarian counterparts.

Ovarian endometrioid tumors with yolk sac tumor component, an unusual form of ovarian neoplasm. Analysis of six cases

The clinical, morphological, and immunohistochemical findings in six cases of ovarian endometrioid tumors (five endometrioid carcinomas and one carcinosarcoma) with a yolk sac tumor (YST) component are described. The age of the patients ranged from 31 to 73 years (average, 53), and only two patients were premenopausal. Two cases were stage Ia tumors, three stage III, and one stage IV. A substantial postoperative elevation of alpha-fetoprotein (AFP) was seen in two patients and a mild increase in another two. All six patients had surgery and postoperative cisplatin-based chemotherapy regimens, four of whom died of tumor 3 to 14 months after surgery without response to treatment. Only a stage Ia patient is alive and well 1 year after surgery. The tumors were large (average, 17 cm). Benign endometrioid lesions were found in the homolateral ovary in two cases and in the contralateral ovary in another two. All cases had endometrioid ovarian carcinomas (EOC) of various types admixed with typical YST components. Immunohistochemically, EOC areas differed from YST in their positivity for OC 125, CA 19.9, and nuclear estrogen and progesterone receptors and in their negativity for AFP, which was conspicuously positive in the YST areas. The clinicopathological profile of ovarian endometrioid tumors with YST also differs from that of YST in that it occurs in the same age range as EOC, it shows coexistence of benign endometrioid lesions, and it has a poor response to chemotherapy. The histological pattern in transitional areas may be difficult to differentiate from "endometrioid-like" (enteroblastic) YST and clear cell tumors. Ovarian endometrioid tumors with YST component should be considered a variant of endometrial carcinoma. Its recognition is necessary in view of its unusually aggressive behavior and poor prognosis.

A case of ovarian serous adenocarcinoma suggestive of transformation to an AFP-producing tumor during chemotherapy

Ovarian serous adenocarcinoma with AFP production is very rare. A case involving a 66-year-old woman with an elevated serum AFP level without detectable hepatic involvement. AFP-positive cells were seen in the tumor at the second surgery. Fifty-seven percent of serum AFP from the patient bound Con A, whereas 43% did not. Similarly, 54% of the tumor fluid also bound Con A. These suggest that the serum AFP was similar to that of gastrointestinal tumors and yolk-sac tumors.