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Genetics and exercise: an introduction
Published in Adam P. Sharples, James P. Morton, Henning Wackerhage, Molecular Exercise Physiology, 2022
Claude Bouchard, Henning Wackerhage
It is important to understand the distinction between germ cells and somatic cells. Male and female germ cells, sperm and oocyte, respectively, are termed gametes. A mature germ cell has only 22 autosomes plus one sex chromosome (i.e. 23 chromosomes in total) in its nucleus instead of the full complement of 46 chromosomes seen in somatic cells (i.e. body cells or non-germ cells). A germ cell containing 23 chromosomes is said to be “haploid”, whereas normal somatic cells contain a “diploid” set of chromosomes. When a haploid sperm and a haploid oocyte fuse, they form a diploid, fertilized oocyte, termed zygote, which is the first cell of the new organism. It has 2 × 22 autosomes plus either two X chromosomes (XX, a female) or an X and a Y (XY, a male) chromosome.
Germ-Cell Cancer of the Testis and Related Neoplasms
Published in Pat Price, Karol Sikora, Treatment of Cancer, 2020
A number of patients with germ-cell tumors present with symptoms from extra-gonadal disease. The most common symptoms in this situation are lumbar backache secondary to metastatic para-aortic lymphadenopathy. Where this disease is bulky there may be obstruction of the ureters(s) leading to hydronephrosis, bowel obstruction, or inferior vena cava occlusion (secondary to either tumor or vascular thrombus). Patients may also present with the signs and symptoms of deep vein thrombosis or pulmonary emboli. Patients with metastatic germ cell tumors (GCT) may present with lung metastases, manifested by chest pain, dyspnea, cough, or hemoptysis. Metastatic disease in the lung can be rapidly progressive, particularly in the choriocarcinoma syndrome,20 in which widespread vascular dissemination is common. Rarely, patients present with an inguinal lymph-node mass—usually a result of previous inguinal/scrotal surgery with resulting anomalous lymphatic drainage—or with a cervical nodal mass. Symptoms can arise due to involvement of the brain (e.g. headaches and fits) and bone (pain) though these represent a small proportion of presentations.
Knowledge Area 14: Gynaecological Oncology
Published in Rekha Wuntakal, Ziena Abdullah, Tony Hollingworth, Get Through MRCOG Part 1, 2020
Rekha Wuntakal, Ziena Abdullah, Tony Hollingworth
A 16-year-old woman presents to emergency gynaecology with abdomen distention and pain. Ultrasound scan of abdomen and pelvis shows solid/cystic mass. Her tumour markers reveal raised AFP and beta-human chorionic gonadotropin (β-hCG). A germ cell tumour is indicated on staging CT scan following discussion at multidisciplinary meeting at cancer centre.
Balancing efficacy with long-term side-effects: can we safely de-escalate therapy for germ cell tumors?
Published in Expert Review of Anticancer Therapy, 2023
The long-term effects of chemotherapy and/or radiotherapy in managing germ cell tumors are significant. While the results with the current standard options in terms of cancer control are very good, the price being paid in terms of long-term side effects is considerable. In some areas of research such as metastatic seminoma, viable alternatives exist (single-agent carboplatin, the potential use of retroperitoneal lymph node dissection as a chemotherapy-sparing approach). These would reduce long-term side effects but may be at the risk of increased recurrence and death. The difficulty of insisting on randomized controlled trials before practice change can occur is that the trials would require thousands of patients and recruitment would take 5–10 years. An alternative would be agreed data capture of new treatments aided by online long-term follow-up recording allowing late effects to be identified.
Pediatric Primary Yolk Sac Tumour of the Kidney: Recommendations for Pretreatment Diagnosis
Published in Fetal and Pediatric Pathology, 2023
Shilpi Thakur, Aanchal Kakkar, Manisha Jana, Prasenjit Das, Sandeep P. Agarwala, Venkateswaran K. Iyer
Germ cell tumors (GCTs) arise from differentiation of primordial germ cells. They most frequently occur in the gonads, but can arise at extra-gonadal sites, either in midline or non-midline locations. Extra-gonadal GCTs account for 1–2.5% of all GCTs, most commonly occur in the mediastinum and retroperitoneum, and have been reported at other unusual locations such as nasal sinuses, prostate, vagina and stomach [6]. Yolk sac tumor (YST) is a malignant GCT resembling extraembryonic structures including yolk sac, allantois, and extraembryonic mesenchyme [7, 8]. GCTs arising in unusual extragonadal locations are often unsuspected clinically, and due to their wide morphological spectrum, may resemble more common primary malignancies occurring in that organ. In core biopsies, all morphological features may not be evident, further enhancing the difficulty and resulting in erroneous diagnosis. We present an intrarenal YST initially misdiagnosed as Wilms tumor on core biopsy, which on resection was a YST, to emphasize that not all pediatric renal tumors are nephroblastoma. A pre-operative alpha-fetoprotein may have helped avoid this misdiagnosis.
Neoplasia in Turner syndrome: a retrospective cohort study in a tertiary referral centre in Belgium
Published in Acta Clinica Belgica, 2022
Cas Dejonckheere, Carolien Moyson, Francis de Zegher, Leen Antonio, Griet Van Buggenhout, Brigitte Decallonne
At present, the gene responsible for the increased risk of gonadoblastoma (hypothetically called GBY or gonadoblastoma locus on the Y chromosome) has not yet been identified. However, its location has been narrowed down to a 4 Mb pericentromeric region on the Y chromosome and it is known to be different from the SRY (sex-determining region of the Y chromosome) gene [33,34]. Several authors have suggested the TSPY (testis-specific protein Y-encoded) gene as a candidate for GBY [35,36]. Although its exact role remains unknown, it is believed to have a general promoting function in the development of germ cell tumours. In addition, prolonged expression of the embryonic germ cell marker OCT3/4 has been linked to malignant transformation. Detection of TSPY, OCT3/4, and other germ cell markers allows to characterise the disturbed process of germ cell maturation on biopsies of dysgenetic gonads. Another important factor in the pathway leading to germ cell tumour development is stem cell factor (SCF). This marker is consistently detected in gonadoblastoma and can be used to differentiate from simple maturation delay. The exact tumour pathogenesis thus proves to be complex, involving a subtle interplay of genetic susceptibility, epigenetic, and microenvironmental parameters (e.g. change in endocrine environment) [9,37,38]. Efforts should be made to send pathology specimens to well-equipped, specialised centres for expert diagnosis, in order to maximise information on the presence of (pre)malignant germ cells and thus improve individual risk assessment.