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.

Human induced pluripotent stem cells (iPSCs) hold great promise for personalized medicine, as they can be differentiated into specific cell types, especially mesenchymal stem cells (MSCs). Therefore, our study sought to assess the feasibility of deriving MSCs from teratomas generated from human iPSCs. Teratomas serve as a model to mimic multilineage human development, thus enriching specific somatic progenitors and stem cells. Here, we discovered a small, condensed mass of MSCs within iPSC-generated teratomas. Afterward, we successfully isolated MSCs from this condensed mass, which was a byproduct of teratoma development. To evaluate the characteristics and cell behaviors of iPSC-derived MSCs (iPSC-MSCs), we conducted comprehensive assessments using qPCR, immunophenotype analysis, and cell proliferation-related assays. Remarkably, iPSC-MSCs exhibited an immunophenotype resembling that of conventional MSCs, and they displayed robust proliferative capabilities, similar to those of higher pluripotent stem cell-derived MSCs. Furthermore, iPSC-MSCs demonstrated the ability to differentiate into multiple lineages in vitro. Finally, we evaluated the therapeutic potential of iPSC-MSCs using an osteochondral defect model. Our findings demonstrated that teratomas are a promising source for the isolation of condensed MSCs. More importantly, our results suggest that iPSC-MSCs derived from teratomas possess the capacity for tissue regeneration, highlighting their promise for future therapeutic applications.

Pluripotent stem cell research has revolutionized the modern era for the past 14 years with the advent of induced pluripotent stem cells. Before this time, scientists had access to human and mouse embryonic stem cells primarily for basic research and an attempt towards lineage-specific differentiations for cell therapy applications. Regarding pluripotent stem cells, expression of bonafide marker proteins such as Oct4, Nanog, Sox2, Klf4, c-Myc, and Lin28 have been considered giving a perfect readout for pluripotent stem cells and assessed using an analytical flow cytometer. In addition to the intracellular markers, surface markers such as stage-specific embryonic antigen-1 for mouse cells and SSEA-4 for human cells are needed to sort pure populations of stem cells for further downstream applications for cell therapy. The surface marker SSEA-4 is the most appropriate for obtaining pure populations of human pluripotent stem cells. When differentiated in a controlled manner using growth factors or small molecules, it is mandatory to assess the downregulation of pluripotency markers (Oct4, Nanog, Sox2, and Klf4) with subsequent up-regulation of stage-specific differentiation markers. Such assessments are done using flow cytometry. Pluripotent stem cells have a high teratoma-forming potential in vivo. Small amounts of undifferentiated PSCs might lead to dangerous teratomas upon transplantation if leftover in the pool of differentiated cells. Hence, flow cytometry is essential for sorting out PSC populations with teratoma-forming potential. The pure populations of differentiated progenitors need to be flow-sorted before differentiating them further for cell therapy applications. For example, Glycoprotein 2 is a specific cell-surface marker for pancreatic progenitors that enables one to sort the pancreatic progenitors differentiated from human PSCs. Taken together, analytical flow cytometry, and cell sorting provide indispensable tools in PSC research and cell therapy.

Cervical teratoma is a rare form of teratoma in neonates and is an unusual cause of cervical masses in them. Teratomas are unusual tumors derived from all 3 germs cell layers: endoderm, mesoderm, and ectoderm, with varying proportions. The cervical teratoma is a rare entity. Its prognosis mostly depends on the risk of neonatal respiratory distress, its extension and potential malignancy. Surgical management must be as complete as possible to avoid recurrences and malignant transformation. We report a case of a cervical immature teratoma in an infant with total excision and cure. No recurrence has been reported. The aim of our study is to review the diagnosis, management and outcomes of congenital cervical teratomas. Cervical teratoma although uncommon should be considered in the differential diagnosis of neck masses in neonates. Teratomas are rare tumors derived from all three germ cell layers affecting the neck in 3% of all cases. An early complete surgical approach to congenital cervical teratomas allows good results with low rates of complication and recurrence.

Ovarian strumal carcinoid is a rare tumor in which thyroid (struma) and carcinoid components coexist. The disease is generally considered to be a borderline malignancy, however, cases with metastatic disease have been described. No data in the literature are available to guide diagnosis and therapy.
We performed a pooled analysis and a systematic review of histopathological-confirmed strumal carcinoid cases published in the literature using the following keywords: \"strumal carcinoid of the ovary\", \"strumal carcinoid case report\". A case of strumal carcinoid tumor diagnosed and followed-up at the Medical Oncology Unit of Spedali Civili (Brescia, Italy) was also described and included.
Sixty-six eligible publications were identified, providing data from one hundred and seventeen patients, plus a case diagnosed at our institution. At presentation, among the eighty-eight patients with symptomatic disease, 37% of patients suffered from abdominal distention and 49% from pain due to a growing abdominal tumor mass, 37% from constipation (peptide YY was analyzed in only nine of them, resulting above the physiologic range). Surgery was the primary therapy in 99% of the patients. Three patients had metastatic disease at diagnosis and five patients underwent recurrence after radical surgery. Histology at disease recurrence concerned the thyroid component in two patients, the carcinoid component in two patients, both histologies in one patient. Median disease-free survival and overall survival in this series were not attained.
Strumal carcinoid of the ovary generally presents a benign behavior and surgery is curative in most cases. However, a small group of patients with this disease can undergo disease recurrence due to both the thyroid and the neuroendocrine (carcinoid) components. A follow-up in radically operated patients is therefore needed, particularly in those with a voluminous disease at diagnosis.

Retrorectal or presacral tumors are rare lesions located in the presacral area and considered as being derived from multiple embryological remnants. These tumors are classified as congenital, neurogenic, osseous, inflammatory, or miscellaneous. The most common among these are congenital benign lesions that present with non-specific symptoms, such as lower back pain and change in bowel habit. Although congenital and developmental tumors occur in younger patients, the median age of presentation is reported to be 45 years. Magnetic resonance imaging plays a crucial role in treatment management through accurate diagnosis of the lesion, the evaluation of invasion to adjacent structures, and the decision of appropriate surgical approach. The usefulness of preoperative biopsy is still debated; currently, it is only indicated for solid or heterogeneous tumors if it will alter the treatment management. Surgical resection with clear margins is considered the optimal treatment; described approaches are transabdominal, perineal, combined abdominoperineal, and minimally invasive. Benign retrorectal tumors have favorable long-term outcomes with a low incidence of recurrence, whereas malignant tumors have a potential for distant organ metastasis in addition to local recurrence.

Several tumors arise from different structures within the mediastinum. Although each type of mediastinal tumor has a predilection for a specific compartment, the progression of growth from one compartment to another can occur. The anterior mediastinum is the site of several tumors that pose interesting diagnostic and therapeutic challenges to thoracic surgeons. The anterior mediastinum is the seat of the majority of neoplastic growths within the mediastinum. Thymomas and lymphomas are the most common pathologies of the anterior mediastinum. Tumors of mesenchymal origin (hemangioma, lymphangioma, lipomas) and their malignant counterparts may occur in any of the mediastinal compartments. Less common tumors of the anterior mediastinal compartment are ectopic thyroid and parathyroid tumors, germ cell tumors, mesenchymal origin tumors, hemangiomas, and cervicomediastinal hygromas. Most of the mediastinal growths usually remain clinically silent until they become large and cause compressive symptoms. Here, we present a case series of five anterior mediastinal tumors consisting of solitary benign teratoma, fibrous benign tumor, malignant fibrosarcoma, hamartomatous chondroma, and malignant thymoma.

The Ter mutation in Dead-End 1 (Dnd1), Dnd1Ter, which leads to a premature stop codon, has been determined to be the cause for primordial germ cell deficiency, accompanied with a high incidence of congenital testicular germ cell tumors (TGCTs) or teratomas in the 129/Sv-Ter mice. As an RNA-binding protein, DND1 can bind the 3\'-untranslated region (3\'-UTR) of mRNAs and function in translational regulation. DND1 can block microRNA (miRNA) access to the 3\'-UTR of target mRNAs, thus inhibiting miRNA-mediated mRNA degradation and up-regulating translation or can also function to degrade or repress mRNAs. Other mechanisms of DND1 activity include promoting translation initiation and modifying target protein activity. Although Dnd1Ter mutation causes spontaneous TGCT only in male 129 mice, it can also cause ovarian teratomas in mice when combined with other genetic defects or cause germ cell teratomas in both genders in the WKY/Ztm rat strain. Furthermore, studies on human cell lines, patient cancer tissues, and the use of human cancer genome analysis indicate that DND1 may possess either tumor-suppressive or -promoting functions in a variety of somatic cancers. Here we review the involvement of DND1 in cancers, including what appears to be its emerging role in somatic cancers.

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.

In response to signals from the embryonic testis, the germ cell intrinsic factor NANOS2 coordinates a transcriptional program necessary for the differentiation of pluripotent-like primordial germ cells toward a unipotent spermatogonial stem cell fate. Emerging evidence indicates that genetic risk factors contribute to testicular germ cell tumor initiation by disrupting sex-specific differentiation. Here, using the 129.MOLF-Chr19 mouse model of testicular teratomas and a NANOS2 reporter allele, we report that the developmental phenotypes required for tumorigenesis, including failure to enter mitotic arrest, retention of pluripotency and delayed sex-specific differentiation, were exclusive to a subpopulation of germ cells failing to express NANOS2. Single-cell RNA sequencing revealed that embryonic day 15.5 NANOS2-deficient germ cells and embryonal carcinoma cells developed a transcriptional profile enriched for MYC signaling, NODAL signaling and primed pluripotency. Moreover, lineage-tracing experiments demonstrated that embryonal carcinoma cells arose exclusively from germ cells failing to express NANOS2. Our results indicate that NANOS2 is the nexus through which several genetic risk factors influence tumor susceptibility. We propose that, in the absence of sex specification, signals native to the developing testis drive germ cell transformation.