Undetectable anti-Mullerian hormone and inhibin B do not preclude the presence of germ cell tumours in 45,X/46,XY or 46,XY gonadal dysgenesis.

OBJECTIVE: Individuals with 45,X/46,XY or 46,XY gonadal dysgenesis are at increased risk of germ cell malignancies. Therefore, prophylactic bilateral gonadectomy is advised in girls and considered in boys with atypical genitalia for undescended, macroscopically abnormal gonads. However, severely dysgenetic gonads may not contain germ cells rendering gonadectomy unnecessary. Therefore, we investigate if undetectable preoperative serum anti-Müllerian hormone (AMH) and inhibin B can predict the absence of germ cells, (pre)malignant or otherwise. DESIGN, PATIENTS AND MEASUREMENTS: Individuals who had undergone bilateral gonadal biopsy and/or gonadectomy because of suspected gonadal dysgenesis in 1999-2019 were included in this retrospective study if preoperative AMH and/or inhibin B were available. Histological material was reviewed by an experienced pathologist. Haematoxylin and eosin and immunohistochemical stainings for SOX9, OCT4, TSPY and SCF (KITL) were used. RESULTS: Thirteen males and 16 females were included, 20 with 46,XY and 9 with 45,X/46,XY DSD. Three females had dysgerminoma alongside gonadoblastoma; two gonadoblastoma, one germ cell neoplasia in situ (GCNIS) and three males had pre-GCNIS and/or pre-gonadoblastoma. Gonadoblastoma and/or dysgerminoma were present in 3/11 individuals with undetectable AMH and inhibin B, one of whom also had non-(pre)malignant germ cells. Of the other 18, in whom AMH and/or inhibin B were detectable, only one had no germ cells. CONCLUSIONS: Undetectable serum AMH and inhibin B cannot reliably predict the absence of germ cells and germ cell tumours in individuals with 45,X/46,XY or 46,XY gonadal dysgenesis. This information should help in counselling about prophylactic gonadectomy, taking into account both the germ cell cancer risk and potential for gonadal function.

Napabucasin overcomes cisplatin resistance in ovarian germ cell tumor-derived cell line by inhibiting cancer stemness.

BACKGROUND: Cisplatin resistance of ovarian yolk sac tumors (oYST) is a clinical challenge due to dismal patient prognosis, even though the disease is extremely rare. We investigated potential association between cisplatin resistance and cancer stem cell (CSC) markers in chemoresistant oYST cells and targeting strategies to overcome resistance in oYST. METHODS: Chemoresistant cells were derived from chemosensitive human oYST cells by cultivation in cisplatin in vitro. Derivative cells were characterized by chemoresistance, functional assays, flow cytometry, gene expression and protein arrays focused on CSC markers. RNAseq, methylation and microRNA profiling were performed. Quail chorioallantoic membranes (CAM) with implanted oYST cells were used to analyze the micro-tumor extent and interconnection with the CAM. Tumorigenicity in vivo was determined on immunodeficient mouse model. Chemoresistant cells were treated by inhibitors intefering with the CSC properties to examine the chemosensitization to cisplatin. RESULTS: Long-term cisplatin exposure resulted in seven-fold higher IC50 value in resistant cells, cross-resistance to oxaliplatin and carboplatin, and increased migratory capacity, invasiveness and tumorigenicity, associated with hypomethylation of differentially methylated genes/promotors. Resistant cells exhibited increased expression of prominin-1 (CD133), ATP binding cassette subfamily G member 2 (ABCG2), aldehyde dehydrogenase 3 isoform A1 (ALDH3A1), correlating with reduced gene and promoter methylation, as well as increased expression of ALDH1A3 and higher overall ALDH enzymatic activity, rendering them cross-resistant to DEAB, disulfiram and napabucasin. Salinomycin and tunicamycin were significantly more toxic to resistant cells. Pretreatment with napabucasin resensitized the cells to cisplatin and reduced their tumorigenicity in vivo. CONCLUSIONS: The novel chemoresistant cells represent unique model of refractory oYST. CSC markers are associated with cisplatin resistance being possible targets in chemorefractory oYST.

Molecular heterogeneity and early metastatic clone selection in testicular germ cell cancer development.

BACKGROUND: Testicular germ cell cancer (TGCC), being the most frequent malignancy in young Caucasian males, is initiated from an embryonic germ cell. This study determines intratumour heterogeneity to unravel tumour progression from initiation until metastasis. METHODS: In total, 42 purified samples of four treatment-resistant nonseminomatous (NS) TGCC were investigated, including the precursor germ cell neoplasia in situ (GCNIS) and metastatic specimens, using whole-genome and targeted sequencing. Their evolution was reconstructed. RESULTS: Intratumour molecular heterogeneity did not correspond to the supposed primary tumour histological evolution. Metastases after systemic treatment could be derived from cancer stem cells not identified in the primary cancer. GCNIS mostly lacked the molecular marks of the primary NS and comprised dominant clones that failed to progress. A BRCA-like mutational signature was observed without evidence for direct involvement of BRCA1 and BRCA2 genes. CONCLUSIONS: Our data strongly support the hypothesis that NS is initiated by whole-genome duplication, followed by chromosome copy number alterations in the cancer stem cell population, and accumulation of low numbers of somatic mutations, even in therapy-resistant cases. These observations of heterogeneity at all stages of tumourigenesis should be considered when treating patients with GCNIS-only disease, or with clinically overt NS.

Imprints and DPPA3 are bypassed during pluripotency- and differentiation-coupled methylation reprogramming in testicular germ cell tumors.

Testicular germ cell tumors (TGCTs) share germline ancestry but diverge phenotypically and clinically as seminoma (SE) and nonseminoma (NSE), the latter including the pluripotent embryonal carcinoma (EC) and its differentiated derivatives, teratoma (TE), yolk sac tumor (YST), and choriocarcinoma. Epigenomes from TGCTs may illuminate reprogramming in both normal development and testicular tumorigenesis. Herein we investigate pure-histological forms of 130 TGCTs for conserved and subtype-specific DNA methylation, including analysis of relatedness to pluripotent stem cell (ESC, iPSC), primordial germ cell (PGC), and differentiated somatic references. Most generally, TGCTs conserve PGC-lineage erasure of maternal and paternal genomic imprints and DPPA3 (also known as STELLA); however, like ESCs, TGCTs show focal recurrent imprinted domain hypermethylation. In this setting of shared physiologic erasure, NSEs harbor a malignancy-associated hypermethylation core, akin to that of a diverse cancer compendium. Beyond these concordances, we found subtype epigenetic homology with pluripotent versus differentiated states. ECs demonstrate a striking convergence of both CpG and CpH (non-CpG) methylation with pluripotent states; the pluripotential methyl-CpH signature crosses species boundaries and is distinct from neuronal methyl-CpH. EC differentiation to TE and YST entails reprogramming toward the somatic state, with loss of methyl-CpH but de novo methylation of pluripotency loci such as NANOG Extreme methyl-depletion among SE reflects the PGC methylation nadir. Adjacent to TGCTs, benign testis methylation profiles are determined by spermatogenetic proficiency measured by Johnsen score. In sum, TGCTs share collective entrapment in a PGC-like state of genomic-imprint and DPPA3 erasure, recurrent hypermethylation of cancer-associated targets, and subtype-dependent pluripotent, germline, or somatic methylation.

Conventional Autopsy versus Minimally Invasive Autopsy with Postmortem MRI, CT, and CT-guided Biopsy: Comparison of Diagnostic Performance.

Purpose To compare the diagnostic performance of minimally invasive autopsy with that of conventional autopsy. Materials and Methods For this prospective, single-center, cross-sectional study in an academic hospital, 295 of 2197 adult cadavers (mean age: 65 years [range, 18-99 years]; age range of male cadavers: 18-99 years; age range of female cadavers: 18-98 years) who died from 2012 through 2014 underwent conventional autopsy. Family consent for minimally invasive autopsy was obtained for 139 of the 295 cadavers; 99 of those 139 cadavers were included in this study. Those involved in minimally invasive autopsy and conventional autopsy were blinded to each other's findings. The minimally invasive autopsy procedure combined postmortem MRI, CT, and CT-guided biopsy of main organs and pathologic lesions. The primary outcome measure was performance of minimally invasive autopsy and conventional autopsy in establishing immediate cause of death, as compared with consensus cause of death. The secondary outcome measures were diagnostic yield of minimally invasive autopsy and conventional autopsy for all, major, and grouped major diagnoses; frequency of clinically unsuspected findings; and percentage of answered clinical questions. Results Cause of death determined with minimally invasive autopsy and conventional autopsy agreed in 91 of the 99 cadavers (92%). Agreement with consensus cause of death occurred in 96 of 99 cadavers (97%) with minimally invasive autopsy and in 94 of 99 cadavers (95%) with conventional autopsy (P = .73). All 288 grouped major diagnoses were related to consensus cause of death. Minimally invasive autopsy enabled diagnosis of 259 of them (90%) and conventional autopsy 224 (78%); 200 (69%) were found with both methods. At clinical examination, the cause of death was not suspected in 17 of the 99 cadavers (17%), and 124 of 288 grouped major diagnoses (43%) were not established. There were 219 additional clinical questions; 189 (86%) were answered with minimally invasive autopsy and 182 (83%) were answered with conventional autopsy (P = .35). Conclusion The performance of minimally invasive autopsy in the detection of cause of death was similar to that of conventional autopsy; however, minimally invasive autopsy has a higher yield of diagnoses. © RSNA, 2018 Online supplemental material is available for this article. See also the editorial by Krombach in this issue.

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-ß, napsin-A, cytokeratin 7 (CK7), PAX8, EMA, AFP, SALL4, villin, glypican-3 (GPC-3), GATA3, HepPar-1, OCT4, CDX2, CD30 and SOX2. HNF1-ß, 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.

Germ cell neoplasia in situ (GCNIS): evolution of the current nomenclature for testicular pre-invasive germ cell malignancy.

The pre-invasive lesion associated with post-pubertal malignant germ cell tumours of the testis was first recognized in the early 1970s and confirmed by a number of observational and follow-up studies. Until this year, this scientific story has been confused by resistance to the entity and disagreement on its name. Initially termed 'carcinoma in situ' (CIS), it has also been known as 'intratubular germ cell neoplasia, unclassified' (IGCNU) and 'testicular intraepithelial neoplasia' (TIN). In this paper, we review the history of discovery and controversy concerning these names and introduce the reasoning for uniting behind a new name, endorsed unanimously at the World Health Organization (WHO) consensus classification 2016: germ cell neoplasia in situ (GCNIS).

Non-invasive or minimally invasive autopsy compared to conventional autopsy of suspected natural deaths in adults: a systematic review.

OBJECTIVES: Autopsies are used for healthcare quality control and improving medical knowledge. Because autopsy rates are declining worldwide, various non-invasive or minimally invasive autopsy methods are now being developed. To investigate whether these might replace the invasive autopsies conventionally performed in naturally deceased adults, we systematically reviewed original prospective validation studies. MATERIALS AND METHODS: We searched six databases. Two reviewers independently selected articles and extracted data. Methods and patient groups were too heterogeneous for meaningful meta-analysis of outcomes. RESULTS: Sixteen of 1538 articles met our inclusion criteria. Eight studies used a blinded comparison; ten included less than 30 appropriate cases. Thirteen studies used radiological imaging (seven dealt solely with non-invasive procedures), two thoracoscopy and laparoscopy, and one sampling without imaging. Combining CT and MR was the best non-invasive method (agreement for cause of death: 70 %, 95%CI: 62.6; 76.4), but minimally invasive methods surpassed non-invasive methods. The highest sensitivity for cause of death (90.9 %, 95%CI: 74.5; 97.6, suspected duplicates excluded) was achieved in recent studies combining CT, CT-angiography and biopsies. CONCLUSION: Minimally invasive autopsies including biopsies performed best. To establish a feasible alternative to conventional autopsy and to increase consent to post-mortem investigations, further research in larger study groups is needed. KEY POINTS: • Health care quality control benefits from clinical feedback provided by (alternative) autopsies. • So far, sixteen studies investigated alternative autopsy methods for naturally deceased adults. • Thirteen studies used radiological imaging modalities, eight tissue biopsies, and three CT-angiography. • Combined CT, CT-angiography and biopsies were most sensitive diagnosing cause of death.

Complete androgen insensitivity syndrome: factors influencing gonadal histology including germ cell pathology.

Patients with complete androgen insensitivity syndrome are at an increased risk for the development of gonadal germ cell cancer. Residual androgen receptor (AR) activity and abnormal gonadal location may influence the survival of atypical germ cells and the development of other histopathological features. To assess this, we evaluated 37 gonads from 19 patients with complete androgen insensitivity (ranging in age from 3 months to 18 years). Histological abnormalities were examined using hematoxylin and eosin-stained sections and sections stained for POU5F1 and KITLG, markers of early changes in germ cells at risk for malignant transformation. Hamartomatous nodules (HNs), Leydig cell hyperplasia (LCH), decreased germ cells, tubular atrophy and stromal fibrosis were more pronounced as age increased (P<0.001). Expected residual AR activity acted as a positive predictor only for non-malignant germ cell survival in (post)pubertal patients (P<0.05). Immunohistochemical studies indicated that delayed maturation of germ cells was present in three patients, whereas intermediate changes that occurred between delayed maturation and intratubular germ cell neoplasia, designated pre-intratubular germ cell neoplasia, were identified in four cases. Intratubular germ cell neoplasia was observed in one patient. Neither POU5F1 nor KITLG expression was dependent on expected residual AR activity. An independent effect of inguinal versus abdominal position of the gonads was difficult to assess because inguinal gonads were present primarily in the youngest individuals. In conclusion, many histological changes occur increasingly with age. Expected residual AR activity contributes to better survival of the general germ cell population in (post)pubertal age; however, it did not seem to have an important role in the survival of the germ cells at risk for malignant transformation (defined by POU5F1 positivity and KITLG overexpression) in complete androgen insensitivity. Comparison of the high percentage of patients in our study that were carrying germ cells with delayed maturation or pre-intratubular germ cell neoplasia with previously reported cumulative risk of tumor development in adult patients indicates that not all such precursor lesions in complete androgen insensitivity will progress to invasive germ cell cancer.