Current developments in human stem cell research and clinical translation
Christine Hauskeller, Arne Manzeschke, Anja Pichl in The Matrix of Stem Cell Research, 2019
Functionally, truly pluripotent iPSCs, such as ES cells, demonstrate three germ layer differentiation potential in vitro and in vivo. In vitro, this potential is assessed with spontaneous differentiation cultures (EB assays) in which iPSCs are cultured as three-dimensional aggregates, referred to as embryoid bodies (EB) (Asprer and Lakshmipathy, 2015). This way embryonic development is mimicked and differentiated cultures are analysed for the expression of germ layer specific genes. In vivo, the pluripotency of human iPSCs is evaluated by teratoma formation (Maherali and Hochedlinger, 2008; Asprer and Lakshmipathy, 2015). A teratoma is an encapsulated tumour containing tissues of all three germ layers. For a teratoma assay, iPSCs are subcutaneously injected into immunodeficient mice and after four to nine weeks the developed tumour is histologically examined for structures of the three germ layers. However, due to a lack of standardization and to ethical concerns regarding animal experiments, teratoma assays are no longer considered the gold standard for human iPSC characterization. Instead, gene expression and DNA methylation profiles (see above) are used to assess pluripotency (Asprer and Lakshmipathy, 2015).
Tumors of the Nervous System
Philip B. Gorelick, Fernando D. Testai, Graeme J. Hankey, Joanna M. Wardlaw in Hankey's Clinical Neurology, 2020
Types of germ cell tumors include: Germinoma.Embryonal carcinoma.Yolk sac tumor.Choriocarcinoma.Mature teratoma.Immature teratoma.Mixed germ cell tumor.
Benign Adnexal Masses and Adnexal Torsion
Juan Luis Alcázar, María Ángela Pascual, Stefano Guerriero in Ultrasound of Pelvic Pain in the Non-Pregnant Female, 2019
Several studies including small case series have shown that mature cystic teratomas tend to slowly grow (1–1.3 mm per year) during conservative management.28,32,33 However, follow-up time was short for most of these studies. Pascual et al. followed women with an ultrasound diagnosis of mature teratoma (n = 408) with the longest follow-up.34 They reported that 103 women underwent surgery during follow-up, most of them during the first 5 years after diagnosis. They found one case of ovarian torsion (0.2%) and two borderline ovarian tumors (0.4%). The main reason for surgery in these cases was increased tumor size (growing 4.8 mm/year) of the remaining 278 women who did not undergo surgery, and no significant change in tumor size was observed with a median follow-up time of 45.6 months (range: 6–147 months). Women who did not undergo surgery had smaller lesions at diagnosis, were older, and had bilateral lesions less frequently than those who ultimately underwent surgery. These authors concluded that expectant management might be a reasonable option for benign-appearing mature teratomas in asymptomatic women.
Biology of Cancer; From Cellular Cancerogenesis to Supracellular Evolution of Malignant Phenotype
Published in Cancer Investigation, 2018
Teratoma is a form of tumor resulting from abnormal generation and evolution of specific pluripotent cells (germ cells or embryonal cells), resuming internal developmental lineage of blastocyst (embryoblast). Variable (1–3) germinal layers of embryo are generated (21), which further can lead to developing of the corresponding tissues and organs (hair, teeth, eyes, hands, feet, brain matter, etc.). There are described mature and immature forms of teratoma, as well as teratomas with malignant evolution (22). Consequently, embryological reprogramming within an adult organism is possible, as proved by occurrence and development of teratoma. In addition, this embryological process seems to be interconnected (at least for immature forms) with malignant transformation. Very suggestive from the perspective of cancerogenesis, malignant teratoma may contain several components related to “conventional” malignancies such as leukemia, carcinoma, or sarcoma (22,23).
Outcome of pediatric germ cell tumor with comparison of carboplatin and cisplatin based regimens: A 10-year analysis
Published in Pediatric Hematology and Oncology, 2022
Richa Jain, Prema Menon, Deepak Bansal, Nandita Kakkar, Srinivasan Radhika, K. L. N. Rao, Amita Trehan
Data of all patients with extracranial germ cell tumor ≤ 12 years age presenting from January 2007-December 2016 (10-years) to the Pediatric Hematology-Oncology Unit at our institute were analyzed. Approval was obtained from our institute’s ethics committee, with a waiver for consent from the patients due to the retrospective nature of analysis. Patients with mature/immature teratoma were included in this analysis. Diagnostic investigations included (i) tumor markers, serum alpha-fetoprotein and beta-human chorionic gonadotropin (AFP, β-HCG), (ii) tissue diagnosis with biopsy or fine-needle aspiration cytology was restricted to cases wherein tumor markers were not elevated, (iii) imaging of the primary site with either a contrast-enhanced computed tomography (CT) or a magnetic resonance imaging. Staging investigations included (i) chest radiograph (till December 2011) or chest CT (2012-2016), (ii) technetium 99 bone scan, and (iii) bone marrow examination if indicated. The staging was based on the tumor-node-metastasis staging system. Risk stratification was performed as per the UK-CCLG guidelines, and patients were categorized as low, intermediate, and high-risk (Supplemental Table 1).6
Tunical Gliomatosis: An Uncommon Histological Entity
Published in Fetal and Pediatric Pathology, 2022
Sabita Patra, Subhankar Chakravorty, Uttara Chatterjee, Koushik Saha
A full term baby boy presented with a lump at the base of the spine. CT scan of the abdomen revealed a large, retroperitoneal mass with an intra-pelvic component with solid and cystic areas. Tumor markers showed a marginally raised serum alpha feto protein (AFP) and human chorionic gonadotrophin (hCG) was within normal limits. The mass was excised along with the coccyx and measured approximately 12 cm. across with mainly solid areas. Histological examination showed features of an immature teratoma with an admixture of skin, glial tissue, cartilage with respiratory epithelium and gut epithelium. There was primitive neuroepithelium present along with immature renal tissue composed of glomeruli, tubules and blastema (Figure 1a–c). A histological diagnosis of immature teratoma, grade II was made. In view of the good prognosis of these tumors in the neonatal age group, no chemotherapy was administered.