Spatial genomic diversity associated with APOBEC mutagenesis in squamous cell carcinoma arising from ovarian teratoma.

Although the gross and microscopic features of squamous cell carcinoma arising from ovarian mature cystic teratoma (MCT-SCC) vary from case to case, the spatial spreading of genomic alterations within the tumor remains unclear. To clarify the spatial genomic diversity in MCT-SCCs, we performed whole-exome sequencing by collecting 16 samples from histologically different parts of two MCT-SCCs. Both cases showed histological diversity within the tumors (case 1: nonkeratinizing and keratinizing SCC and case 2: nonkeratinizing SCC and anaplastic carcinoma) and had different somatic mutation profiles by histological findings. Mutation signature analysis revealed a significantly enriched apolipoprotein B mRNA editing enzyme catalytic subunit (APOBEC) signature at all sites. Intriguingly, the spread of genomic alterations within the tumor and the clonal evolution patterns from nonmalignant epithelium to cancer sites differed between cases. TP53 mutation and copy number alterations were widespread at all sites, including the nonmalignant epithelium, in case 1. Keratinizing and nonkeratinizing SCCs were differentiated by the occurrence of unique somatic mutations from a common ancestral clone. In contrast, the nonmalignant epithelium showed almost no somatic mutations in case 2. TP53 mutation and the copy number alteration similarities were observed only in nonkeratinizing SCC samples. Nonkeratinizing SCC and anaplastic carcinoma shared almost no somatic mutations, suggesting that each locally and independently arose in the MCT. We demonstrated that two MCT-SCCs with different histologic findings were highly heterogeneous tumors with clearly different clones associated with APOBEC-mediated mutagenesis, suggesting the importance of evaluating intratumor histological and genetic heterogeneity among multiple sites of MCT-SCC.

Fetal biometric and Doppler measurements following abdominal radical trachelectomy in the second trimester of the pregnancy.

BACKGROUND: Our previous study demonstrated the safety and effectiveness of abdominal radical trachelectomy during pregnancy but did not focus on the fetus. This study aimed to clarify the influence of abdominal radical trachelectomy performed during pregnancy on the fetus. METHODS: Eight cervical cancer patients who underwent abdominal radical trachelectomy at our hospital between February 2013 and August 2020 were enrolled in this study. To assess the peri- and postoperative influence on the fetus, we performed fetal heart monitoring at 30-min intervals during abdominal radical trachelectomy and calculated the estimated fetal body weight and resistance indexes of the middle cerebral artery and umbilical artery from postsurgery until delivery. RESULTS: Four out of eight patients had preterm birth due to chorioamnionitis in one case and consideration of the recurrent risk of cervical cancer in three cases. Fetal heart monitoring during abdominal radical trachelectomy revealed deceleration just once in one case but no abnormal findings in the other cases. In all cases, the fetal growth after abdominal radical trachelectomy was normal until delivery. No abnormal Doppler findings were detected in the middle cerebral artery or umbilical artery. CONCLUSION: Our findings clarified that abdominal radical trachelectomy performed for the treatment of early-stage cervical cancer during pregnancy has no obvious influence on fetal growth. Next, it is necessary to evaluate the growth and development of children delivered from mothers who have undergone abdominal radical trachelectomy during pregnancy.

Enhanced proliferation and differentiation of human mesenchymal stem cells in the gravity-controlled environment.

BACKGROUND: Human bone marrow mesenchymal stem cells (hMSCs) present a promising cell source with the potential to be used for curing various intractable diseases, and it is expected that the development of regenerative medicine employing cell-based therapy would be significantly accelerated when such methods are established. For that, powerful methods for selective growth and differentiation of hMSCs should be developed. METHODS: We developed an efficient method for hMSC proliferation and differentiation into osteoblasts and adipocytes using gravity-controlled environments. RESULTS: The results indicate that the average doubling time of hMSCs cultured in a regular maintenance medium under microgravity conditions (0.001 G) was 1.5 times shorter than that of cells cultured under natural gravity conditions (1.0 G). Furthermore, 99.2% of cells grown in the microgravity environment showed the expression of hMSC markers, as indicated by flow cytometry analysis. Osteogenic and adipogenic differentiation of hMSCs expanded in the microgravity environment was enhanced under microgravity and hypergravity conditions, respectively, as evidenced by the downregulation of hMSC markers and upregulation of osteoblast and adipocyte markers, respectively. Most cells differentiated into osteoblasts in the microgravity environment after 14 days (~80%) and adipocytes in the hypergravity environment after 12 days (~90%). CONCLUSIONS: Our results indicate that hMSC proliferation and selective differentiation into specific cell lineages could be promoted under microgravity or hypergravity conditions, suggesting that cell culture in the gravity-controlled environment is a useful method to obtain cell preparations for potential clinical applications.

Biological significance of KRAS mutant allele expression in ovarian endometriosis.

KRAS is the most frequently mutated in ovarian endometriosis. However, it is unclear whether the KRAS mutant allele's mRNA is expressed and plays a biological role in ovarian endometriosis. Here, we performed mutation-specific RNA in situ hybridization to evaluate mutant allele expression of KRAS p.G12V, the most frequently detected mutation in ovarian endometriosis in our previous study, in formalin-fixed paraffin-embedded tissue (FFPE) samples of ovarian endometriosis, cancer cell lines, and ovarian cancers. First, we verified that mutant or wild-type allele of KRAS were expressed in all 5 cancer cell lines and 9 ovarian cancer cases corresponding to the mutation status. Next, we applied this assay to 26 ovarian endometriosis cases, and observed mutant allele expression of KRAS p.G12V in 10 cases. Mutant or wild-type allele of KRAS were expressed in line with mutation status in 12 available endometriosis cases for which KRAS gene sequence was determined. Comparison of clinical features between ovarian endometriosis with KRAS p.G12V mutant allele expression and with KRAS wild-type showed that KRAS p.G12V mutant allele expression was significantly associated with inflammation in ovarian endometriosis. Finally, we assessed the spatial distribution of KRAS mutant allele expression in 5 endometriosis cases by performing multiregional sampling. Intratumor heterogeneity of KRAS mutant allele expression was observed in two endometriosis cases, whereas the spatial distribution of KRAS p.G12V mutation signals were diffuse and homogenous in ovarian cancer. In conclusion, evaluation of oncogene mutant expression will be useful for clarifying the biological significance of oncogene mutations in benign tumors.

Proposing a molecular classification associated with hypercoagulation in ovarian clear cell carcinoma.

BACKGROUND: Although ovarian clear cell carcinoma (CCC) is associated with high incidence of thromboembolism, the clinicopathological and biological significance of hypercoagulable status in CCC remains unclear. MATERIALS AND METHODS: We retrospectively analyzed pretreatment D-dimer levels, thromboembolic status, and clinical outcome of 125 CCCs in the discovery set and 143 CCCs in two other independent validation sets. Next, we performed RNA sequencing of 93 CCCs and compared coagulation-related gene profiles with 2492 pan-cancer data. We investigated differences in molecular characteristics of CCC subclasses based on coagulation status. RESULTS: In the discovery dataset, D-dimer elevation above the normal range was significantly associated with shorter progression-free and overall survival, irrespective to thromboembolic status. Multivariate analysis identified D-dimer elevation and clinical stage as an independent prognostic factors. We confirmed the prognostic significance of D-dimer elevation in the validation sets. Tissue factor and IL6, which are considered key elements of cancer-induced hypercoagulation, were highly expressed in CCC than in other cancers regardless of D-dimer level. Higher activity of various oncogenic pathways was observed in CCC with compared to without D-dimer elevation. Moreover, hierarchical cluster analysis divided 57 CCCs with D-dimer elevation into immunologically hot and cold tumor subtypes. Hot tumors were characterized by enrichment of T-cell inflamed phenotype, inflammation, the epithelial-mesenchymal transition, and high serum levels of CRP, and cold tumors by enrichment of cell cycle and MYC pathways. CONCLUSIONS: CCC represents hypercoagulable disease and elevate D-dimer is a prognostic factor for decreased survival in CCC. D-dimer high CCC has distinct molecular characteristics into the inflammatory-driven pathway (hot tumor) and the immune-suppressive pathway (cold tumor). Treatment implication of our proposed molecular classification merits further investigation.

Enlarged uterine fibroid forming uterine diverticulum during pregnancy: a case report.

BACKGROUND: Although uterine fibroids are a common gynecologic neoplasm, uterine diverticulum accompanied by a uterine fibroid is unique. In addition, pregnancy complicated with uterine diverticulum is extremely rare. We experienced a case of a uterine fibroid that was associated with a uterine diverticulum that enlarged during pregnancy and puerperium. CASE PRESENTATION: A 25-year-old nulligravida woman had an abnormal uterine cavity surrounded by myomatous mass. After natural conception, the mass and pouch had enlarged during pregnancy. Six months after elective cesarean delivery, she underwent laparotomy because of abdominal pain caused by the myomatous mass and the fluid inside. The tumor was connected to the midline of the posterior wall of the normal uterus. The resected tumor was pathologically diagnosed as leiomyoma and diverticulum. CONCLUSIONS: Pregnancy can stimulate uterine fibroids to form uterine diverticula. Resection of the diverticulum and fibroid is a useful option for symptomatic patients with desired future fertility.

PET/MR imaging for the evaluation of cervical cancer during pregnancy.

BACKGROUND: Malignancy during pregnancy is increasing, and the most common type of malignancy is uterine cervical cancer. When planning the treatment of cervical cancer, it is important to look for signs of metastasis before surgery, especially metastasis to the lymph nodes. In this report, we assessed the diagnostic value of positron emission tomography/magnetic resonance imaging (PET/MRI) for evaluating cervical cancer propagation before surgery, with a focus on pregnant women. CASE PRESENTATION: 18F Fluorodeoxyglucose (FDG)-PET/MRI was performed in seven pregnant cervical cancer patients (28-34 years old) at 9-18 gestational weeks. In case #5, a second PET/MRI was performed at 24 gestational weeks. Of seven FDG-PET/MRI examination series in six cases (cases #1-6), FDG-PET/MR imaging could detect cervical tumors with abnormal FDG accumulation; these tumors were confirmed with a standardized uptake value max (SUV max) titer of 4.5-16. A second PET/MRI examination in case #5 revealed the same SUV max titer as the first examination. In these six imaging series (cases #1-5), there were no signs of cancer metastasis to the parametrium and lymph nodes. However, in case #6, abnormal FDG accumulation in the left parametrial lymph nodes was also detectable. Pathological examination showed lymph node metastasis in case #6. In case #7, PET/MRI could not detect any abnormal FDG accumulation in the cervix and other sites. Cone biopsy demonstrated only micro-invasive squamous cell carcinoma. After treatment for cervical cancer, all seven patients have had no recurrence of disease within the follow-up period (2.8-5.6 years), and their children have developed appropriately. CONCLUSION: PET/MRI is an effective imaging tool to evaluate cervical cancer progression in pregnancy.

Different mutation profiles between epithelium and stroma in endometriosis and normal endometrium.

STUDY QUESTION: Are there common mutation profiles between epithelial and stromal cells in ovarian endometriotic tissue and the normal endometrium? SUMMARY ANSWER: Our study revealed no common mutations between epithelial and stromal cells in ovarian endometriotic tissue and the normal endometrium. WHAT IS KNOWN ALREADY: Epithelial cells in both ovarian endometriotic tissue and the normal endometrium harbor somatic mutations in cancer-associated genes such as phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha (PIK3CA) and KRAS proto-oncogene, GTPase (KRAS). STUDY DESIGN, SIZE, DURATION: We performed a retrospective study to identify the mutation profiles of stromal cells in endometriotic tissue and the normal endometrium. We collected 11 endometriotic stroma samples and 10 normal endometrial stroma samples between 2013 and 2017 at a tertiary care center. PARTICIPANTS/MATERIALS, SETTING, METHODS: The laser microdissection method was used to obtain stromal cells in ovarian endometriotic and normal endometrial tissues from patients with ovarian endometriosis and/or other non-invasive gynecological diseases. Target gene sequencing was performed to assess and compare the mutation profiles of stromal cells with those of epithelial cells obtained in our previous study. For target gene sequencing, 76 genes were selected based on previous genomic analyses for ovarian endometriosis, normal endometrium, endometriosis-related ovarian cancer and endometrial cancer. MAIN RESULTS AND THE ROLE OF CHANCE: Stromal samples in ovarian endometrioma and normal endometrium harbor somatic mutations (18 mutations in 11 endometriosis samples and 16 mutations in 10 normal endometrial samples) but did not share any mutations with paired epithelial samples. The mutant allele frequency of stromal samples was significantly lower than that of epithelial samples in ovarian endometrioma (P = 6.0 × 10-11) and normal endometrium (P = 1.4 × 10-7). LIMITATIONS, REASONS FOR CAUTION: The number of genes evaluated in the mutational analysis was limited. Additionally, the functional roles of somatic mutations in stromal cells remain unclear. WIDER IMPLICATIONS OF THE FINDINGS: Different mutation profiles between paired epithelial and stromal cells in both ovarian endometrioma and normal endometrium suggest that origins of epithelial and stromal cells would be independent of each other in both normal endometrium and ovarian endometrioma; however, the theory of epithelial-mesenchymal transition is proposed in ovarian endometrioma. STUDY FUNDING/COMPETING INTEREST(S): This work was supported in part by the Japan Society for the Promotion of Science KAKENHI grant number JP15H02373 (Grant-in-Aid for Scientific Research A for I.I.), JP16H06267 (Grant-in-Aid for Young Scientists A for K.Y.), JP17K08688 (Grant-in-Aid for Scientific Research C for H.N.) and JP16H06279 (Grant-in-Aid for Scientific Research on Innovative Areas-Platforms for Advanced Technologies and Research Resources for H.N. and K.Y). There are no conflicts of interest to declare. TRIAL REGISTRATION NUMBER: Not applicable.

Ectopic pregnancy following oral levonorgestrel emergency contraception use.

Levonorgestrel is used worldwide as an emergency oral contraceptive. There have been occasional reports of ectopic pregnancy after oral levonorgestrel use. We present a case of ectopic tubal pregnancy after the use of oral levonorgestrel as an emergency contraceptive in a 37-year-old woman with a history of treatment for Chlamydia trachomatis infection. She conceived after sexual intercourse on menstrual day 14 of the first menstrual cycle following a normal delivery. After salpingectomy for this right tubal pregnancy, her following pregnancy was an ectopic pregnancy in the contralateral tube, which was treated with laparoscopic salpingectomy. Histopathological examination revealed endometriosis. We should be aware of ectopic pregnancy even after emergency contraceptive use, especially in patients with risk factors, such as Chlamydia infection and endometriosis. Because the efficacy of levonorgestrel decreases after ovulation, we should check the stage of the cycle before prescription.

The Safety and Effectiveness of Abdominal Radical Trachelectomy for Early-Stage Cervical Cancer During Pregnancy.

OBJECTIVES: Cervical cancer is one of the most frequently diagnosed cancers in pregnancy. Our aim was to evaluate the safety and efficacy of abdominal radical trachelectomy (ART) for pregnant women with early-stage cervical cancer who strongly desire to preserve their pregnancies. METHODS/MATERIALS: A retrospective observational study was performed for stage IB1 cervical cancer patients who underwent ART or radical hysterectomy (RH) at our hospital between February 2013 and June 2017. We compared differences in perioperative findings and oncologic outcomes among ART during pregnancy (ART-DP), ART, and RH groups. RESULTS: A total of 38 patients were included in this analysis. Six, 10, and 22 patients were assigned to the ART-DP, ART, and RH groups, respectively. There were no significant differences in the distribution of pathological TNM classifications, histology, tumor size, stromal invasion, and lymph-vascular space invasion among the 3 groups. The patients in the ART-DP group were younger than those in the RH group (P = 0.014). The ART-DP group was associated with more blood loss and prolonged surgery compared with the RH group (P = 0.017 and P = 0.014). The number of total lymph nodes in the ART-DP group was lower than that in the RH group (P = 0.036). However, there were no significant differences in age, surgical time, blood loss, or lymph node count between the ART-DP and ART groups. There were no significant differences in progression-free and overall survival times among the 3 groups, and no recurrence was observed in the ART-DP group. CONCLUSIONS: Abdominal radical trachelectomy may be a tolerable treatment option for pregnant women with early-stage cervical cancer who strongly desire a baby.

Myomectomy scar ectopic pregnancy following a cryopreserved embryo transfer.

CASE: A 40 year old woman with a history of a myomectomy visited the Department of Obstetrics and Gynecology, Niigata University Medical and Dental Hospital, Niigata, Japan, following 2 years of infertility. Magnetic resonance imaging detected an abnormal endometrial-like pseudo-cavity. A hysterosalpingography also revealed an abnormal accumulation of contrast medium at the myometrial scar site. A transvaginal ultrasound showed a thin myometrium at the lower uterine body. The patient conceived via in vitro fertilization under a luteal phase down-regulation protocol (long protocol) for controlled ovarian stimulation, followed by a cryopreserved embryo transfer during her natural ovulation cycle. After the embryo transfer, the gestational sac was located at the subserosal site of the myomectomy scar. OUTCOME: An emergent laparoscopic operation was performed and the embryo was removed successfully via laparoscopy under transvaginal ultrasonography. CONCLUSION: A subserosal uterine pregnancy is a rare form of intramural pregnancy, which is a rare subtype of an ectopic pregnancy, which could occur at the myomectomy site, especially after an embryo transfer. It is believed that this rare ectopic pregnancy resulted from embryo implantation under the serosa through a micro-sinus tract that was a site of suture failure of the myomectomy scar and was partially affected by the embryo transfer. Clinicians should consider the possibility of an ectopic pregnancy after uterine surgery, including a myomectomy.

Microdissection testicular sperm extraction in five Japanese patients with non-mosaic Klinefelter's syndrome.

CASES: Microdissection testicular sperm extraction (micro-TESE) was performed on five Japanese men with non-mosaic Klinefelter's syndrome (KS) and non-obstructive azoospermia in the authors' department. Here is reported the operative results and partner's clinical course for two cases where spermatozoa could be acquired. Also encountered was a man with non-mosaic KS with the partial deletion of azoospermia factor (AZF)b. Because this is rare, it is reported in detail in the context of the previous literature. This case series describes the first experience of micro-TESE by gynecologists in the current department. OUTCOME: The egg collection date was adjusted to the micro-TESE day by using the modified ultra-long method. Intracytoplasmic sperm injection (ICSI) was implemented for two men whose spermatozoa were acquired by micro-TESE, with these progressing to the blastocyst stage. Subsequently, one case conceived after the transfer of fresh embryos and a healthy baby was delivered. However, spermatozoa could not be retrieved from the man with non-mosaic KS who was harboring the partial deletion of AZFb. CONCLUSION: These findings suggest that ovulation induction by using the modified ultra-long method with micro-TESE and ICSI on the same day represents an effective treatment option for men with non-mosaic KS. As there are cases where AZF deletion is recognized among patients with non-mosaic KS, screening before micro-TESE is strongly recommended.

Tumor-derived spheroids: Relevance to cancer stem cells and clinical applications.

Recently, many types of in vitro 3-D culture systems have been developed to recapitulate the in vivo growth conditions of cancer. The cancer 3-D culture methods aim to preserve the biological characteristics of original tumors better than conventional 2-D monolayer cultures, and include tumor-derived organoids, tumor-derived spheroids, organotypic multicellular spheroids, and multicellular tumor spheroids. The 3-D culture methods differ in terms of cancer cell sources, protocols for cell handling, and the required time intervals. Tumor-derived spheroids are unique because they are purposed for the enrichment of cancer stem cells (CSCs) or cells with stem cell-related characteristics. These spheroids are grown as floating spheres and have been used as surrogate systems to evaluate the CSC-related characteristics of solid tumors in vitro. Because eradication of CSCs is likely to be of clinical importance due to their association with the malignant nature of cancer cells, such as tumorigenicity or chemoresistance, the investigation of tumor-derived spheroids may provide invaluable clues to fight against cancer. Spheroid cultures have been established from cancers including glioma, breast, colon, ovary, and prostate cancers, and their biological and biochemical characteristics have been investigated by many research groups. In addition to the investigation of CSCs, tumor-derived spheroids may prove to be instrumental for a high-throughput screening platform or for the cultivation of CSC-related tumor cells found in the circulation or body fluids.

Sox2-dependent inhibition of p21 is associated with poor prognosis of endometrial cancer.

Sex-determining region Y-box 2 (SOX2) is an essential factor involved in the self-renewal and pluripotency of embryonic stem cells and has functions in cell survival and progression in many types of cancers. Here, we found that several endometrial cancer cell lines expressed SOX2, which was required for cell growth. Additionally, SOX2 overexpression regulated the expression of cyclin-dependent kinase inhibitor 1A (CDKN1A), and SOX2 specifically bound to p21 promoter DNA in endometrial cancer cell lines expressing SOX2. Expressions of SOX2 in endometrial cancer patients were significantly correlated with histological grade and poor prognosis. Moreover, low p21 together with high SOX2 expressions in advanced endometrial cancer patients were associated with the most unfavorable outcomes of patients. These results indicated that simultaneous measurement of SOX2 and p21 expression in endometrial cancer patients may be a useful biomarker for patient prognosis.

Fetiform teratoma was a parthenogenetic tumor arising from a mature ovum.

The aim of this study was to investigate the parthenogenetic origin of fetiform teratoma by using molecular genetic studies and methylation status analyses. A fetiform teratoma was removed from a 35-year-old nulligravida woman. Genotyping of microsatellite marker loci, microarray analysis of single-nucleotide polymorphism (SNP) loci and methylation status analysis of the differentially methylated region (DMR) within the human IGF2-H19 locus were performed. Karyotypes of the host and the fetiform teratoma were 46, XX. The fetiform teratoma was homozygous at all loci and meiotic recombinations in the tumor were confirmed by SNP microarray analysis. Methylation analysis indicated that the host had both methylated and unmethylated IGF2-H19 DMR alleles, while the fetiform teratoma had unmethylated alleles only. Genetically, the fetiform teratoma had homozygous genotypes with meiotic recombination and a duplicated unmethylated host allele, indicating that it was a parthenogenetic tumor arising from a mature ovum after meiosis II. This is the first demonstration of a fetiform teratoma originating from a mature haploid ovum.

Combination of large-volume sample stacking with an electroosmotic flow pump with field-amplified sample injection on cross-channel chips.

A combination of two online sample concentration techniques, large-volume sample stacking with an electroosmotic flow (EOF) pump (LVSEP) and field-amplified sample injection (FASI), was investigated in microchip electrophoresis (MCE) to achieve highly sensitive analysis. By applying reversed-polarity voltages on a cross-channel microchip, anionic analytes injected throughout a microchannel were first concentrated on the basis of LVSEP, followed by the electrokinetic stacking injection of the analytes from a sample reservoir by the FASI mechanism. As well as the voltage application, a pressure was also applied to the sample reservoir in LVSEP-FASI. The applied pressure generated a counter-flow against the EOF to reduce the migration velocity of the stacked analytes, especially around the cross section of the microchannel, which facilitated the FASI concentration. At the hydrodynamic pressure of 15 Pa, 4520-fold sensitivity increase was obtained in the LVSEP-FASI analysis of a standard dye, which was 33-times higher than that obtained with a normal LVSEP. Furthermore, the use of the sharper channel was effective for enhancing the sensitivity, e.g., 29 100-fold sensitivity increase was achieved with the 75-µm wide channel. The developed method was applied to the chiral analysis of amino acids in MCE, resulting in the sensitivity enhancement factor of 2920 for the separated d-leucine.

Biochemical analysis of intraplacental choriocarcinoma and fetomaternal transfusion.

Intraplacental choriocarcinoma is one of the rarest forms of gestational tumors and is believed to be one of the causes of fetomaternal transfusion (FMT). A 35-year-old woman, gravida 2, para 2, with a history of two vaginal deliveries, was incidentally diagnosed as having stage I gestational intraplacental choriocarcinoma with a FIGO/World Health Organization 2000 risk score of 2 after term delivery. This disease caused neonatal anemia but did not metastasize to either the mother or infant. Short tandem repeat analysis with laser microdissection revealed that the tumor had originated from the current pregnancy. Serological test and immunohistochemical analysis revealed that the patient and her baby suffered from FMT. She has been free from disease without any medical intervention for the last 1 year. A combination of multiple biochemical analyses might help us diagnose the precursor pregnancy of a gestational choriocarcinoma and FMT.

Recurrent ovarian undifferentiated carcinoma resembling hepatoid morphology treated with pegylated liposomal doxorubicin and bevacizumab.

Hepatoid carcinomas are undifferentiated epithelial carcinomas that are pathologically similar to hepatocellular carcinoma, but occur in a variety of organs. Hepatoid carcinomas, as strictly defined, typically produce α-fetoprotein. In addition, a standard effective chemotherapy regimen for hepatoid carcinoma has yet to be established. We present a case of advanced primary ovarian cancer that was pathologically similar to hepatoid carcinoma without staining for α-fetoprotein or hepatocyte paraffin 1. The primary ovarian, metastatic, and recurrent tumors shared similar pathological characteristics. Fourth-line chemotherapy with pegylated liposomal doxorubicin and bevacizumab was effective in treating the recurrent tumor, even though this disease had recurred three times.

Gestational choriocarcinoma: Rare spinal metastasis during a viable pregnancy.

Gestational choriocarcinoma metastasizing to the bones, especially to the spine, is extremely rare. In addition, there are few reports of choriocarcinoma during a viable pregnancy. We report a case of gestational choriocarcinoma that metastasized to the lumbar spine during a viable pregnancy in a 41-year-old woman with a history of a missed abortion. A heterogeneous cervical mass was detected at gestational week 16. Subsequently, a metastatic lesion appeared during the pregnancy, and fetal demise in utero occurred. Pathological examination revealed that the cervical tumor and metastatic spinal tumor were choriocarcinoma. The patient's condition deteriorated rapidly and we were unable to save her life, despite multidrug chemotherapy. Surgical tumor resection and pregnancy might involve a substantial risk of choriocarcinoma metastasis. It is important to obtain an early diagnosis for this life-threatening disease in order to facilitate appropriate treatment, despite pregnancy.

miR-493 induction during carcinogenesis blocks metastatic settlement of colon cancer cells in liver.

Liver metastasis is a major lethal complication associated with colon cancer, and post-intravasation steps of the metastasis are important for its clinical intervention. In order to identify inhibitory microRNAs (miRNAs) for these steps, we performed 'dropout' screens of a miRNA library in a mouse model of liver metastasis. Functional analyses showed that miR-493 and to a lesser extent miR-493(*) were capable of inhibiting liver metastasis. miR-493 inhibited retention of metastasized cells in liver parenchyma and induced their cell death. IGF1R was identified as a direct target of miR-493, and its inhibition partially phenocopied the anti-metastatic effects. High levels of miR-493 and miR-493(*), but not pri-miR-493, in primary colon cancer were inversely related to the presence of liver metastasis, and attributed to an increase of miR-493 expression during carcinogenesis. We propose that, in a subset of colon cancer, upregulation of miR-493 during carcinogenesis prevents liver metastasis via the induction of cell death of metastasized cells.