Defining the Teratoma as a Model for Multi-lineage Human Development.

We propose that the teratoma, a recognized standard for validating pluripotency in stem cells, could be a promising platform for studying human developmental processes. Performing single-cell RNA sequencing (RNA-seq) of 179,632 cells across 23 teratomas from 4 cell lines, we found that teratomas reproducibly contain approximately 20 cell types across all 3 germ layers, that inter-teratoma cell type heterogeneity is comparable with organoid systems, and teratoma gut and brain cell types correspond well to similar fetal cell types. Furthermore, cellular barcoding confirmed that injected stem cells robustly engraft and contribute to all lineages. Using pooled CRISPR-Cas9 knockout screens, we showed that teratomas can enable simultaneous assaying of the effects of genetic perturbations across all germ layers. Additionally, we demonstrated that teratomas can be sculpted molecularly via microRNA (miRNA)-regulated suicide gene expression to enrich for specific tissues. Taken together, teratomas are a promising platform for modeling multi-lineage development, pan-tissue functional genetic screening, and tissue engineering.

A rare germline BMP15 missense mutation causes hereditary ovarian immature teratoma in human.

Ovarian immature teratomas (OITs) are malignant tumors originating from the ovarian germ cells that mainly occur during the first 30 y of a female's life. Early age of onset strongly suggests the presence of susceptibility gene mutations for the disease yet to be discovered. Whole exon sequencing was used to screen pathogenic mutations from pedigrees with OITs. A rare missense germline mutation (C262T) in the first exon of the BMP15 gene was identified. In silico calculation suggested that the mutation could impair the formation of mature peptides. In vitro experiments on cell lines confirmed that the mutation caused an 84.7% reduction in the secretion of mature BMP15. Clinical samples from OIT patients also showed a similar pattern of decrease in the BMP15 expression. In the transgenic mouse model, the spontaneous parthenogenetic activation significantly increased in oocytes carrying the T allele. Remarkably, a mouse carrying the T allele developed the phenotype of OIT. Oocyte-specific RNA sequencing revealed that abnormal activation of the H-Ras/MAPK pathway might contribute to the development of OIT. BMP15 was identified as a pathogenic gene for OIT which improved our understanding of the etiology of OIT and provided a potential biomarker for genetic screening of this disorder.

Malignant ovarian and testicular germ cell tumors: Common characteristics but different prognoses.

Both ovarian and testicular germ cell tumors (GCTs) arise from the primordial germ cell and share many similarities. Both malignancies affect mainly young patients, show remarkable responsiveness to cisplatin-based therapy, and have an excellent prognosis, which also highlights the importance of minimizing long-term side effects. However, certain differences can be noted: The spreading of the disease differs, and the staging system and treatment recommendations are dissimilar. Moreover, the prognosis for ovarian GCTs is significantly inferior to that for testicular cancer, as exemplified in this review comparing the survival in Swedish patients diagnosed with testicular (1995-2022) and ovarian (1990-2018) GCTs. The 5-year overall survival in ovarian GCTs was 85.2%, versus 98.2% for testicular GCTs. How can this be explained? One reason may be the difference in knowledge, experience, and evidence because the incidence rate of testicular cancer is more than 15 times that of ovarian GCTs. Given the rarity of the disease in women and the lack of established guidelines, a comprehensive understanding of the disease and treatment decisions is challenging. The main objective of this review is to derive insights from testicular GCTs (seminoma and non-seminoma) by reviewing etiological, tumor biological, and clinical knowledge, and to thereafter suggest actions for ovarian GCTs based on this. We hypothesize that by adopting specific treatment strategies from testicular GCTs-including de-escalating adjuvant chemotherapy for low-risk patients and implementing more standardized and intensive treatment protocols in cases of relapse-we can improve the prognosis and minimize long-term side effects in ovarian GCT patients.

Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy to Treat Pseudomyxoma Peritonei of Ovarian Origin: A Retrospective French RENAPE Group Study.

BACKGROUND: Ovarian pseudomyxoma peritonei (OPMP) are rare, without well-defined therapeutic guidelines. We aimed to evaluate cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) to treat OPMP. METHODS: Patients from the French National Network for Rare Peritoneal Tumors (RENAPE) database with proven OPMP treated by CRS/HIPEC and with histologically normal appendix and digestive endoscopy were retrospectively included. Clinical and follow-up data were collected. Histopathological and immunohistochemical features were reviewed. RESULTS: Fifteen patients with a median age of 56 years were included. The median Peritoneal Cancer Index was 16. Following CRS, the completeness of cytoreduction (CC) score was CC-0 for 9/15 (60%) patients, CC-1 for 5/15 (33.3%) patients, and CC-2 for 1/15 (6.7%) patients. The median tumor size was 22.5 cm. After pathological review and immunohistochemical studies, tumors were classified as Group 1 (mucinous ovarian epithelial neoplasms) in 3/15 (20%) patients; Group 2 (mucinous neoplasm in ovarian teratoma) in 4/15 (26.7%) patients; Group 3 (mucinous neoplasm probably arising in ovarian teratoma) in 5/15 (33.3%) patients; and Group 4 (non-specific group) in 3/15 (20%) patients. Peritoneal lesions were OPMP pM1a/acellular, pM1b/grade 1 (hypocellular) and pM1b/grade 3 (signet-ring cells) in 13/15 (86.7%), 1/15 (6.7%) and 1/15 (6.7%) patients, respectively. Disease-free survival analysis showed a difference (p = 0.0463) between OPMP with teratoma/likely-teratoma origin (groups 2 and 3; 100% at 1, 5, and 10 years), and other groups (groups 1 and 4; 100%, 66.6%, and 50% at 1, 5, and 10 years, respectively). CONCLUSION: These results suggested that a primary therapeutic strategy using complete CRS/HIPEC for patients with OPMP led to favorable long-term outcomes.

Dermoid cyst management and outcomes: a review of over 1000 cases at a single institution.

BACKGROUND: Mature cystic teratomas represent nearly 60% of benign ovarian neoplasms across all age groups. OBJECTIVE: This study aimed to update existing descriptive studies of ovarian teratomas, including the epidemiology, rate of torsion or malignancy, and treatment modalities in a large modern cohort of patients. STUDY DESIGN: This was a retrospective cross-sectional study of all pathology-confirmed cases of ovarian teratoma that underwent surgery at 1 tertiary care institution from 2004 to 2015. Patient demographics, ovarian cyst characteristics, surgical approach and timing, rate of spillage, and surgical complications were examined. RESULTS: A total of 1054 cases of ovarian teratoma were identified during the study period. There were 113 cases (10.7%) of bilateral teratoma. The mean age at diagnosis was 38 years. The average cyst size was 6.26 cm. The overall rate of torsion was 5.6%, with a higher rate of torsion with increasing cyst size. More than 70% of cases were treated with minimally invasive surgery, which was associated with decreased perioperative complications but an increased risk of cyst spillage. Among 394 patients with cyst spillage, only 1 patient developed chemical peritonitis. The malignant transformation rate of mature cystic teratoma in this cohort was 1.1%. This cohort included 100 pregnant women with mature teratoma. Pregnant patients were more likely to have minimally invasive surgery in the first trimester of pregnancy and more likely to undergo laparotomy in the second or third trimester of pregnancy. CONCLUSION: Similar rates of bilaterality, torsion, malignant transformation, and struma ovarii in ovarian teratomas were found in this large modern cohort compared with previous literature. Most cases of ovarian teratoma can be managed laparoscopically, which is associated with a lower surgical complication rate. Despite the increased risk of cyst spillage with a minimally invasive approach, chemical peritonitis is a rare complication.

Non-invasive differential diagnosis of teratomas from other intracranial germ cell tumours using MRI-based fractal and radiomic analyses.

OBJECTIVES: The histologic subtype of intracranial germ cell tumours (IGCTs) is an important factor in deciding the treatment strategy, especially for teratomas. In this study, we aimed to non-invasively diagnose teratomas based on fractal and radiomic features. MATERIALS AND METHODS: This retrospective study included 330 IGCT patients, including a discovery set (n = 296) and an independent validation set (n = 34). Fractal and radiomic features were extracted from T1-weighted, T2-weighted, and post-contrast T1-weighted images. Five classifiers, including logistic regression, random forests, support vector machines, K-nearest neighbours, and XGBoost, were compared for our task. Based on the optimal classifier, we compared the performance of clinical, fractal, and radiomic models and the model combining these features in predicting teratomas. RESULTS: Among the diagnostic models, the fractal and radiomic models performed better than the clinical model. The final model that combined all the features showed the best performance, with an area under the curve, precision, sensitivity, and specificity of 0.946 [95% confidence interval (CI): 0.882-0.994], 95.65% (95% CI: 88.64-100%), 88.00% (95% CI: 77.78-96.36%), and 91.67% (95% CI: 78.26-100%), respectively, in the test set of the discovery set, and 0.944 (95% CI: 0.855-1.000), 85.71% (95% CI: 68.18-100%), 94.74% (95% CI: 83.33-100%), and 80.00% (95% CI: 58.33-100%), respectively, in the independent validation set. SHapley Additive exPlanations indicated that two fractal features, two radiomic features, and age were the top five features highly associated with the presence of teratomas. CONCLUSION: The predictive model including image and clinical features could help guide treatment strategies for IGCTs. CLINICAL RELEVANCE STATEMENT: Our machine learning model including image and clinical features can non-invasively predict teratoma components, which could help guide treatment strategies for intracranial germ cell tumours (IGCT). KEY POINTS: • Fractals and radiomics can quantitatively evaluate imaging characteristics of intracranial germ cell tumours. • Model combing imaging and clinical features had the best predictive performance. • The diagnostic model could guide treatment strategies for intracranial germ cell tumours.

Variability in Surveillance Strategies Following Resection of Sacrococcygeal Teratoma.

INTRODUCTION: Surveillance following sacrococcygeal teratoma (SCT) resection varies. The purpose of this study was to describe the clinical characteristics and outcomes of patients undergoing SCT resection and examine current institutional practices to detect recurrence. METHODS: A single-institution retrospective review of children who underwent resection of an SCT from January 1, 2010 to December 31, 2020 was performed. Data were summarized and surveillance strategies compared between histopathologic subtypes using nonparametric methods. RESULTS: Thirty six patients (75.0% female) underwent SCT removal at a median age of 8 d. Histopathology revealed 27 mature teratomas (75.0%), eight immature teratomas (22.2%), and one malignant germ cell tumor (2.8%). Median postoperative follow-up was 3.17 y (interquartile range [IQR]: 2.31-4.38 y). Patients had a median of 2.32 clinic visits per year (IQR: 2.00-2.70), alpha-fetoprotein levels were obtained at a median of 2.01 times per year (IQR: 0-1.66), and surveillance imaging was performed at a median of 2.31 times per year (IQR: 0-2.84). Patients with immature teratomas had alpha-fetoprotein laboratories obtained more frequently than patients with mature teratomas (3.10 times/year versus 0.93 times/year, P = 0.001). There was no significant difference in the number of imaging studies obtained between groups. Two patients (5.6%) developed recurrence, which were identified on magnetic resonance imaging at 191 and 104 d postresection, respectively. CONCLUSIONS: Postoperative surveillance practices varied widely. Recurrence was noted in a single malignant case in the first year following resection. Multi-institutional studies are needed to determine the optimal surveillance strategy to detect recurrence of SCT.

Impact of microscopic deposits of yolk sac tumor on recurrence of mature sacrococcygeal teratoma.

INTRODUCTION: Sacrococcygeal teratomas (SCT) with malignant histology frequently recur and are treated aggressively, but risk factors and surveillance protocols are less established for mature tumors. In particular, prior studies have not investigated whether microscopic deposits of yolk sac tumor (YST) in otherwise mature teratomas lead to higher recurrence rates. METHODS: We reviewed patients with mature SCTs resected at our institution from 2011 to 2021 and analyzed tumor characteristics, treatment, and outcomes. RESULTS: We identified 56 patients with mature SCT, of which 9 (16%) demonstrated microscopic YST. Following surgery, 7/56 (13%) patients developed local recurrence at a mean of 1.2 ± 0.7 years, while no patients developed metastases. Recurrence was more likely in patients with microscopic YST [5/9 (56%) vs. 2/47 (4%), p = 0.021] and positive margins [6/24 (35%) vs. 1/32 (3.1%), p = 0.030]. A solid tumor component tended to increase recurrence risk as well [6/29 (21%) vs. 1/27 (4%), p = 0.053]. Five patients demonstrated malignant recurrence and were all detected by a rising alpha-fetoprotein (AFP), while two patients demonstrated recurrence of mature teratoma and were detected on surveillance magnetic resonance imaging (MRI). CONCLUSIONS: Microscopic foci of YST may increase recurrence risk for patients with mature SCT. Such patients might benefit from closer postoperative surveillance with serial AFP measurements and MRI.

Growing teratoma syndrome in children and adolescents: Prevalence and surgical outcome.

INTRODUCTION: Patients affected by metastatic germ cell tumors may occasionally experience enlargement of masses with concurrent normalization of tumor markers during or after chemotherapy. This phenomenon is described as growing teratoma syndrome (GTS). The aim of the pre sent study is to assess the prevalence of GTS in the pediatric population and its implications in terms of surgical outcome. PATIENTS AND METHODS: The clinical notes of patients diagnosed with stage III and IV malignant germ cell tumors from January 2010 until December 2020 at our Institution were retrospectively reviewed. The prevalence of GTS, treatment strategies, survival, and outcome were analyzed. RESULTS: Thirty-three patients with high-stage malignant germ cell tumors were diagnosed in our institution in the analyzed period. Nine patients (28%) had radiologic evidence of enlargement of persistent masses with normal markers after chemotherapy; these patients were classified as GTS patients. All nine patients underwent resection of metastatic lymph nodes, and six had surgery on visceral metastases. In six patients, radical excision of all metastatic sites was achieved; five patients are alive and in complete remission, while one died because of peri-operative complications. Out of the three patients who could not achieve radical excision of the metastases, two died of progressive disease, and one is alive with progressive disease. CONCLUSIONS: Patients affected by GTS have a risk of progression of chemotherapy-resistant disease and death. Radical surgical excision is essential to achieve disease control and long-term survival.

A rare case of retroperitoneal teratoma with evidence of papillary thyroid carcinoma: a case report.

BACKGROUND: Teratomas are germ cell tumors composed of somatic tissues from up to three germ layers. Primary retroperitoneal teratomas usually develop during childhood and are uncommon in adults and in the retroperitoneal space. While there are only a few cases of retroperitoneal thyroid tissue, we report a unique case of a retroperitoneal papillary thyroid carcinoma. CASE PRESENTATION: A 41-year-old woman presented in our institution due to intermitted unspecific abdominal pain. Magnetic resonance imaging detected a multi-cystic solid retroperitoneal mass ventral to the psoas muscle and the left iliac artery. After surgical removal of the retroperitoneal mass, histology sections of the specimen indicated evidence of papillary thyroid carcinoma cells. A staging computed tomography scan of the body showed no further manifestations. To reduce the risk of recurrence, total thyroidectomy was performed followed by radioiodine therapy with lifelong hormone substitution. CONCLUSIONS: Primary retroperitoneal teratoma with evidence of papillary thyroid carcinoma is a rare condition. Preoperative diagnosis is difficult due to its non-specific clinical manifestation and lack of specific radiologic findings. Histopathology analysis is necessary for diagnosis. Although surgery is considered the first line treatment, there is still discussion about the extent of resection and the need for total thyroidectomy with adjuvant radioiodine therapy.

Laparoscopic-assisted Fertility-sparing Surgery for Growing Teratoma Syndrome of the Ovary: Experience from a Tertiary Center.

STUDY OBJECTIVE: The main objective is to evaluate the feasibility of laparoscopic fertility-sparing surgery in women with growing teratoma syndrome. DESIGN: Retrospective cohort study. SETTING: Chinese tertiary university hospital. PATIENTS: Patients with growing teratoma syndrome who underwent fertility-sparing surgery between January 2015 and August 2023. INTERVENTIONS: Baseline characteristics and surgical outcomes were evaluated, including clinical information, surgical procedures, operative time, intraoperative blood loss, complications, length of hospital stay, and follow-up information. MEASUREMENT AND MAIN RESULTS: Twenty-six patients with ovarian growing teratoma syndrome underwent fertility-sparing surgery: 12 had laparoscopic surgery and 14 underwent laparotomic surgery. In the laparoscopic group, the median age of the patients during initial management of immature teratoma or mixed malignant ovarian germ cell tumor was 14.0 years (interquartile range, 13.0-24.5 years). Eleven patients were nulliparous. The primary ovarian tumor was pure immature teratoma in 10 patients and mixed ovarian germ cell tumor in 2 patients. Complete laparoscopic tumor resection was achieved in 11 patients. Patients in the laparoscopic group had shorter median operative time (76.5 vs 180.0 minutes, p = .001), lower estimated blood loss (20.0 vs 400.0 mL, p <.001), and decreased postoperative hospital stay (2.0 vs 7.0 days, p <.001) compared with laparotomic surgery. There was no conversion to laparotomy and no perioperative complications. Histologic examination confirmed mature teratoma in all cases. During a median follow-up of 21.9 months (interquartile range, 7.6-44.9 months), 11 patients were alive without disease and 1 was alive with disease. One pregnancy was achieved postoperatively. CONCLUSION: Laparoscopic fertility-sparing surgery may represent a feasible option in well-selected patients with ovarian growing teratoma syndrome. Surgery should be performed in gynecologic oncology centers by experienced staff trained in endoscopic procedures. More research and long-time follow-up are needed to determine the oncologic outcomes and safety of laparoscopic surgery in this population.

Congenital orbital teratoma: a rare case with intracranial extension.

INTRODUCTION: Teratoma is the most common congenital tumor, but the orbital location is rare. It is composed of tissues from ectoderm, mesoderm, and endoderm. CLINICAL PRESENTATION: Congenital orbital teratoma commonly presents as unilateral proptosis, with rapid growth, leading to exposure keratopathy. DIAGNOSIS: Prenatal ultrasound may detect the orbital mass, computed tomography (CT) scans, and magnetic resonance (MR) imaging are better in demonstrating multilocular cystic and solid mass, without bone erosion. Laboratory tests should include alfa-fetoprotein (AFP) and B-human chorionic gonadotropin (B-HCG), and histopathologically, it contains all three germ cell layers components. The management is surgical removal of the lesion, the mature teratoma has a benign behavior, and the immature has a poor prognostic. We describe a rare case of congenital orbital teratoma with intracranial extension of the lesion, in which was treated with orbital exenteration. After surgery, AFP levels decreased, the middle face displacement has improved and development milestones were appropriate.

Vasospasm and subsequent stroke from paraneoplastic syndrome in a pediatric patient with an intracranial mature teratoma: a case report.

Teratomas account for 18-20% of all intracranial germ cell tumors and mostly occur in the pineal region with only a few cases of pediatric sellar and suprasellar teratomas described in the literature. Here, we present a case of a child with an intracranial mature teratoma with pancreatic features causing vasospasm and subsequent stroke, found to be positive for CDKN2A-an independent variant associated with malignancy and small vessel disease leading to stroke.

Simultaneous spine extradural and intradural teratomas in a pediatric patient: A rare presentation with insights in the flawed migration of germ cells theory.

Spinal teratomas are infrequent lesions in the pediatric population. These lesions can be extradural, intradural or intramedullary. We present a case of an 8-month-old boy that was assessed for underdevelopment of motor milestones. The neurologic examination revealed hyporeflexia, decreased sensation and flaccid paraplegia. MRI of the spine revealed two simultaneous and independent lesions in the extradural and intradural compartment. A laminectomy was performed for the T4-T7 vertebrae with total resection of both lesions. The histopathological analysis confirmed both lesions to be mature cystic teratomas. At the 1-year follow-up, the patient remained with no recovery of neurological function. A debate takes place regarding the etiology of formation of these lesions in the spine. The simultaneous presentation of two independent lesions in this patient could contribute to define the flawed migration of germ cells theory as the etiology for formation of teratomatous lesions in the spine.

Suprasellar teratoma to germinoma recurrence: implications for diagnosis and follow-up.

Mature teratoma is a subtype of intracranial germ cell tumors (GCTs), distinguished from malignant GCTs by its benign nature and excellent prognosis. Typically, no adjuvant therapy is recommended following gross total resection (GTR). We report a case of a prepubertal girl with a suprasellar mature teratoma that recurred as a germinoma 6 months post-GTR. A 7-year-old girl presented with headache and polydipsia. Imaging revealed a suprasellar mass. The patient underwent GTR, and pathological diagnosis confirmed a mature teratoma without other GCT components. Six months later, MRI identified a newly developed suprasellar mass adjacent to the optic chiasm. A second surgery confirmed the mass as a germinoma. The patient subsequently underwent adjuvant chemotherapy combined with proton therapy, resulting in complete remission. The diagnosis of mature teratoma must be approached with caution, and thorough follow-up is imperative, particularly in cases involving female patients, prepubertal age, or non-pineal locations.

Prenatal diagnosis of meningomyelocele resolves as a mature cystic teratoma in the thoracolumbar region.

A mature cystic teratoma is a mass with heterogeneous appearance, consisting of adult tissue with two or three layers: endoderm, mesoderm, and ectoderm. It is a rare, benign transformation of somatic tissue most commonly found in the sacrococcygeal region and may resemble an uncomplicated spina bifida on prenatal ultrasonography. In this case report, we describe a female newborn with an extremely rare mature cystic teratoma in the thoracolumbar region. She presented prenatally with a preliminary diagnosis of meningomyelocele, diastematomyelia, and Chiari II malformation and a possible teratoma. However, a mass containing solid glandular tissues and bony calcifications approximately 3 × 4 cm in size was observed in the thoracolumbar region upon birth. During surgical resection, no nerve roots were found in the associated meningocele. The patient retained full lower body function postoperatively following surgical excision of the thecal sac and teratoma.

Pediatric sellar teratoma - Case report and review of the literature.

BACKGROUND: Intracranial teratoma represents a rare neoplasm, occurring predominantly during childhood. Characteristic symptoms depend on the location but are mainly hydrocephalus, visual disturbances, hypopituitarism, and diabetes insipidus. Initial diagnosis can be challenging due to similar radiological features in both teratomas and other lesions such as craniopharyngiomas. Gross total resection is recommended if feasible and associated with a good prognosis. CASE DESCRIPTION: A 10-year-old girl presented with newly diagnosed growth retardation, fatigue, cephalgia and bilateral hemianopia. Further laboratory analysis confirmed central hypothyroidism and hypercortisolism. Cranial magnetic resonance imaging showed a cystic space-occupying lesion in the sellar and suprasellar compartment with compression of the optic chiasm without hydrocephalus present, suspicious of craniopharyngioma. Subsequently, an endonasal endoscopic transsphenoidal near-total tumor resection with decompression of the optic chiasm was performed. During postoperative recovery the patient developed transient diabetes insipidus, the bilateral hemianopia remained unchanged. The patient could be discharged in a stable condition, while hormone replacement for multiple pituitary hormone deficiency was required. Surprisingly, histopathology revealed conspicuous areas of skin with formation of hairs and squamous epithelia, compatible with a mature teratoma. CONCLUSIONS: We present an extremely rare case of pediatric sellar teratoma originating from the pituitary gland and a review of literature focusing on the variation in presentation and treatment. Sellar teratomas are often mistaken for craniopharyngioma due to their similar radiographic appearances. However, the primary goal of treatment for both pathologies is to decompress eloquent surrounding structures such as the optic tract, and if applicable, resolution of hydrocephalus while avoiding damage to the pituitary stalk and especially the hypothalamic structures. If feasible, the aim of surgery should be gross total resection.

Management strategy for children with ovarian immature teratoma: results from a tertiary pediatric oncology center.

OBJECTIVES: We present an Egyptian study on pediatric ovarian immature teratomas (ITs), aiming to clarify our treatment strategy selection. METHODS: A retrospective review of all children with pure ovarian ITs who were treated at our institution between 2008 and 2023. The analysis included clinical characteristics, tumor staging according to Children's Oncology Group (COG), grading based on the Norris system, management, and outcomes. RESULTS: Thirty-two patients were included, with a median age of 9 years. All patients underwent primary surgery. Unilateral salpingo-oophorectomy was performed in 31 patients. Surgical staging was completed in all patients. Based on COG staging, there were 28 patients (87.5%) stage I, 1 (3%) stage II, and 3 (9.5%) stage III. According to Norris classification, 16 patients (50%) were classified as grade I, 9 (28%) grade II, and 7 (22%) grade III. All patients in stage I were treated using surgery-alone approach, whereas the remaining four (12.5%) received adjuvant chemotherapy. Five patients in stage I had gliomatosis peritonei (GP), and none of them underwent extensive surgery. At a median follow-up of 86 months, two patients had events. The first patient (stage III/grade I) developed IT relapse on the operative bed, and the second (stage I/grade I) had a metachronous IT on the contralateral ovary. Both patients were successfully managed with surgery followed by second-line chemotherapy. Five-year overall survival and event-free survival for all patients were 100% and 93.4%, respectively. CONCLUSIONS: Surgery-alone strategy with close follow-up achieves excellent outcomes for localized ovarian ITs in children, irrespective of the Norris grading or the presence of GP. However, adjuvant chemotherapy is questionable for patients with incompletely resected or locally advanced tumors, and its role requires further evaluation through prospective multicentric studies with a larger sample size.

Genetically edited CD34+ cells derived from human iPS cells in vivo but not in vitro engraft and differentiate into HIV-resistant cells.

Genetic editing of induced pluripotent stem (iPS) cells represents a promising avenue for an HIV cure. However, certain challenges remain before bringing this approach to the clinic. Among them, in vivo engraftment of cells genetically edited in vitro needs to be achieved. In this study, CD34+ cells derived in vitro from iPS cells genetically modified to carry the CCR5Δ32 mutant alleles did not engraft in humanized immunodeficient mice. However, the CD34+ cells isolated from teratomas generated in vivo from these genetically edited iPS cells engrafted in all experiments. These CD34+ cells also gave rise to peripheral blood mononuclear cells in the mice that, when inoculated with HIV in cell culture, were resistant to HIV R5-tropic isolates. This study indicates that teratomas can provide an environment that can help evaluate the engraftment potential of CD34+ cells derived from the genetically modified iPS cells in vitro. The results further confirm the possibility of using genetically engineered iPS cells to derive engraftable hematopoietic stem cells resistant to HIV as an approach toward an HIV cure.

Pigmented epithelioid melanocytoma arising from a teratoma of a Carney complex patient.

A 25-year-old female Carney complex patient with a PRKAR1A mutation who had undergone surgery to remove teratomas visited our dermatology department. She was suspected of having a malignant melanoma in a teratoma. On clinical examination, a black nodule was found within the cyst. On histopathological examination, the black lesion was composed of heavily pigmented round cells with vesicular nuclei and single prominent nucleoli. Additionally, there were large cells with irregularly shaped nuclei. Upon immunohistochemical examination, the large, irregularly shaped cells were positively stained with Melan A, HMB45, S-100 protein, SOX10, CD10 (focally), and BRAFV600E , but negatively stained with PRAME. Based on the histopathological features, we diagnosed the patient with pigmented epithelioid melanocytoma (PEM) in a teratoma of a Carney complex patient. This is the first case of PEM developing from a teratoma. Since PEM lesions may spread to regional lymph nodes, careful follow-up is necessary.