Germ cell tumors encompass a broad spectrum of neoplasms arising from germ cell lineage, demonstrating varying histological profiles and clinical presentations. These tumors encompass a range of benign and malignant entities. While global trends provide insights into their prevalence, specific regional variations, such as those within North-Western India, remain less explored. This study seeks to bridge this knowledge gap by examining the prevalence and characteristics of germ cell tumors within a tertiary cancer hospital. In this retrospective analysis, all cases of germ cell tumors diagnosed over a 3-year period in the specified tertiary cancer hospital were included. Cases with incomplete records or inadequate pathological data were excluded. Data encompassing histological subtypes, patient age distribution, clinical presentations, and histopathological features were collected and analyzed. The study comprised 145 cases of germ cell tumors. Teratomas were the most prevalent subtype, with mature teratomas accounting for the majority. The highest incidence occurred within the 21-30-year age group with a mean age of 24.77 years. Abdominal mass (56%) and abdominal pain (34%) were the prominent clinical presentations. Benign cases constituted the majority 85.5%. Solid tumors (p < 0.00001) and tumors more than 10 cm (p .029028) were found to have a high propensity to be malignant, which was proven to be statistically significant. This study comprehensively explains germ cell tumors\' prevalence, clinical features, and histopathological subtypes in a tertiary cancer hospital in North-Western India. The predominance of teratomas, particularly mature ones, aligns with global trends. The age distribution and clinical presentations reflect common patterns. The diverse histopathological appearances underscore the heterogeneous nature of germ cell tumors. This study offers valuable insights for clinical management and further regional research.

Cellular reprogramming is a process by which adult differentiated cells lose their identity and are converted into pluripotent stem cells, known as induced pluripotent stem (iPS) cells. This process can be achieved in vitro and in vivo and is relevant for many fields including regenerative medicine and cancer. Cellular reprogramming is commonly induced by the ectopic expression of a transcription factor cocktail composed by Oct4, Sox2, Klf4, and Myc (abbreviated as OSKM), and its efficiency and kinetics are strongly dependent on the presence of Myc. Here, we describe a versatile method to study reprogramming in vivo based on the use of adeno-associated viral (AAV) vectors, which allows the targeting of specific organs and cell types. This method can be used to test Myc mutations or genes that may replace Myc, or be combined with different Myc regulators. In vivo reprogramming can be scored by the presence of teratomas and the isolation of in vivo iPS, thereby providing a simple surrogate for the function of Myc in dedifferentiation and stemness. Our protocol can be divided into five steps: (1) intravenous inoculation of AAV vectors; (2) monitoring the animals until the appearance of teratomas; (3) analysis of teratomas; (4) histopathological analysis of mouse organs; and (5) isolation of in vivo-generated iPS cells from teratomas, blood, and bone marrow. The information obtained by this in vivo testing platform may provide relevant information on the role of Myc in tissue regeneration, stemness, and cancer.

Human germ cell tumours have been established as transplantable xenografts in immune suppressed and congenitally athymic animals. This review summarises the current and potential uses of this animal model in the study of these tumours, including the generation of \'human\' tumour material for histological, immunocytochemical and ultrastructural analysis, for radio- and chemosensitivity testing, and for the development of new techniques of tumour imaging.