Ovarian Immature Teratoma Research Articles

Mature Ovarian Teratoma and Gliomatosis Peritonei: an Uncommon Case Report

Gliomatosis peritonei (GP) is a rare condition characterized by benign glial implants in the peritoneum, omentum, and lymph nodes, typically associated with immature ovarian teratomas and less frequently with mature teratomas. We present a case of a 21-year-old woman with severe abdominal pain and a large abdominal mass. Imaging revealed a large multilocular cystic mass suggestive of a dermoid cyst with torsion. During exploratory laparotomy, a large cystic mass with hair, teeth, and sebaceous material was found in the left ovary, alongside multiple nodules in the omentum. A left salpingo-oophorectomy, omentectomy, and peritoneal biopsies were performed. Histopathology confirmed a mature teratoma with GP. The patient's postoperative period was uneventful, and no adjuvant therapy was required. This case underscores the importance of recognizing GP in patients with ovarian teratomas, highlighting the typically benign nature and favorable prognosis of GP with proper surgical management.

Fertility outcomes in stage I ovarian immature teratomas

ObjectiveTo evaluate the impact of adjuvant chemotherapy, type of ovarian surgery, and the surgical approach on fertility in patients with stage I immature teratoma of the ovary.MethodsClinicopathologic data were retrospectively...

Imaging of Gliomatosis Peritonei Following an Immature Ovarian Teratoma: A Case Report

Imaging of Gliomatosis Peritonei Following an Immature Ovarian Teratoma: A Case Report

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

ObjectivesWe present an Egyptian study on pediatric ovarian immature teratomas (ITs), aiming to clarify our treatment strategy selection.MethodsA 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.ResultsThirty-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.ConclusionsSurgery-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.

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.

#356 : Concurrent Growing Teratoma Syndrome and Gliomatosis Peritonei in Childbearing Woman with Mature Ovarian Teratoma: A Case Report

Gliomatosis peritonei (GP) is a rare clinical condition associated with ovarian teratomas of any grade, in which benign glial implants develop on the peritoneal surface of the abdomen. Growing teratoma syndrome (GTS) is a rare entity defined as the appearance of benign enlarging peritoneal implants that occur during or after chemotherapy for malignant germ cell tumors but are histologically mature teratomas without any malignant component. Complete surgical resection is essential for the diagnosis and treatment of GTS. We report an association scarcely described in the literature to date, in which both GP and GTS were observed in a patient treated with chemotherapy for immature ovarian teratoma. We encountered a patient with suspected concurrent GTS and Gliomatosis peritonei 2 months after chemotherapy, and a second-look fertility-sparing surgery confirmed the diagnosis. A tumor suspected to be GTS was observed in a nulliparous woman in her 20’s immediately after the completion of three cycles of bleomycin, etoposide, and cisplatin therapy after fertility-sparing surgery for stage IIIb ovarian immature teratoma. As ovarian germ cell tumors are characterized by a young onset, fertility-sparing surgery is performed in most cases. Total tumor resection affects the prognosis of GTS; therefore, minimally invasive surgery before tumor growth is advisable.

Prognostic comparison of active surveillance and adjuvant chemotherapy in the treatment of patients with stage Ⅰ ovarian immature teratoma after fertility-sparing surgery

Objective: To compare the survival outcomes between surveillance and adjuvant chemotherapy in patients with stage Ⅰ ovarian immature teratoma (IMT) underwent fertility-sparing surgery. Methods: Clinical and pathological records of patients with stage Ⅰ ovarian IMT between Jan. 2011 to Feb. 2023 were collected from Peking Union Medical College Hospital, except stage Ⅰa grade 1. The consultation of risks and benefits regarding adjuvant chemotherapy was conducted by gynecologic oncologists. A shared decision about surveillance or chemotherapy was made by physician and patients or their guardians. Patients who finally decided to undergo surveillance were included in the surveillance group (n=40), the others were included in the adjuvant chemotherapy group (n=63). Clinical characteristics, treatment and survival outcomes were analyzed and compared between two groups. Results: A total of 103 patients were included. The median age of initial diagnosis was 20 years old (range: 3-39 years old), and the median follow-up time was 31 months (range: 1-254 months). The age, International Federation of Gynecology and Obstetrics (FIGO) stage, pathological grade, surgical method, and preoperative and postoperative alpha-fetoprotein levels in the surveillance group and the adjuvant chemotherapy group were similar (all P>0.05). The surgical approach and maximum tumor diameter between two groups were significantly different (all P<0.05). Forty patients of the surveillance group were identified, only one patient with stage Ⅰa grade 2 IMT who underwent cystectomy had malignant recurrence on the same ovary. Another 63 patients received adjuvant chemotherapy after surgery, five patients had malignant recurrence, and two of them died of disease progression after relapsed. There were no significant differences in disease-free survival (DFS;20 vs 36 months) and overall survival (OS; 23 vs 39 months) between the surveillance group and the adjuvant chemotherapy group (follow-up time censored at 72 months; DFS: P=0.325, OS: P=0.278). Conclusions: There are no differences in survival outcomes between patients with stage Ⅰ ovarian IMT underwent adjuvant chemotherapy or not. Active surveillance might be safe and preferable in stage Ⅰ IMT patients underwent complete resection of tumor.

Prognostic factors for pure ovarian immature teratoma and the role of adjuvant chemotherapy in stage I diseases

Background The prognostic factors for patients with pure ovarian immature teratoma (POIT) and the role of adjuvant chemotherapy in stage IA G2-G3 and IB-IC POIT remains controversial. Methods We conducted a retrospective study of 155 POIT patients treated in our hospital between 2000 and 2022. The recurrence-free survival (RFS), disease-specific survival (DSS), and potential prognostic factors of POIT patients were evaluated. Subgroup analysis was conducted in stage I other than stage IA G1 POIT. Results The median age at diagnosis was 23.0 years (range: 4.0 − 39.0), and 126 (81.3%), 2 (1.3%), 26 (16.8%), and 1 (0.6%) patients had FIGO stage I, stage II, stage III, and stage IV disease, respectively. Twenty-three patients relapsed and five died of the diseases after a median follow-up of 7.6 years, with a 5-year RFS and DSS rate of 86.0% and 97.0%, respectively. Multivariate analysis showed that positive postoperative tumour markers (TM) were the risk factor for recurrence in the overall cohort (hazard ratio [HR] 4.058, 95% CI 1.175 − 14.019, p = 0.027) and subgroup (HR 10.237, 95% CI 2.175 − 48.179, p = 0.003), and FIGO stage II–IV was the only factor for DSS in overall cohort (HR 7.751, 95% CI 1.281 − 46.895, p = 0.026). In 110 patients subjected to subgroup analysis, 29 patients received surveillance without chemotherapy and 81 patients were administered adjuvant chemotherapy. Multivariate analysis revealed active surveillance significantly increased the recurrence rate (5-year RFS of 75.7% vs. 93.6%, HR 7.562, 95% CI 2.441 − 23.424, p < 0.001) but not the death related to POIT (p = 0.338). Conclusion Positive postoperative TM and FIGO stage II–IV were the prognostic factors for POIT. Active surveillance in stage I POIT of any grade may be practical for those with negative postoperative TM.

EP29.05: Gliomatosis peritonei in a reproductive‐aged nulligravid with a background of ovarian immature teratoma

EP29.05: Gliomatosis peritonei in a reproductive‐aged nulligravid with a background of ovarian immature teratoma

Significance of Ultra-Radical Surgery in Extensive Metastatic Ovarian Growing Teratoma Syndrome

Introduction: The aim of the study was to evaluate the perioperative risks and outcomes of ultra-radical surgery in patients with extensive metastatic ovarian growing teratoma syndrome (GTS). Methods: We conducted a retrospective study of patients with extensive metastatic ovarian GTS treated in our hospital between 2000 and 2022. Patients’ clinical characteristics, surgical treatment, and outcomes were evaluated. Results: Overall, 13 patients were identified, and the median age at diagnosis of ovarian immature teratoma (IT) was 24 years (range: 5–37). The median interval between IT diagnosis and presenting GTS was 8 months (range: 2–60), with a median surgery delay of 5 months (range: 3–300). Peritoneum and liver were the most commonly affected sites (100%), followed by bowel (12 patients, 92.3%), diaphragm (12 patients, 92.3%), adnexa (9 patients, 69.2%), omentum (8 patients, 61.5%), uterus (7 patients, 53.8%), in the descending order. The mean operation time was 316 min (range: 180–625), and the mean blood loss volume was 992 mL (range: 200–5,000). Peritoneal metastasectomy (13 patients, 100%), diaphragmatic metastasectomy (12 patients, 92.3%), metastasis removal from the bowel (8 patients, 61.5%), partial hepatectomy (4 patients, 30.8%), bowel excision and anastomosis (1 patient, 7.7%) were also applied to achieve optimal debulking. R0 was achieved in 9 (69.2%) patients. A high rate of intraoperative blood transfusion (8 patients, 61.5%) and admission to the intensive care unit (9 patients, 69.2%) were observed, and the median postoperative hospitalization time was 8 days (range: 4–22). After a median follow-up of 3.3 years, 9 patients were free of disease, and 4 were alive with stable residual diseases. Conclusion: The survival outcomes in extensive metastatic ovarian GTS were satisfactory after ultra-radical surgery, while a proper therapeutic plan should be established due to the high perioperative risks.

AGCT1531: Evaluating the utility of circulating microRNA in the management of children, adolescents, and adults with malignant germ cell tumors.

TPS5104 Background: Conventional serum tumor markers for malignant germ cell tumors (MGCTs) have limited performance characteristics, especially in non-secreting histologies such as embryonal carcinoma or seminoma. Growing evidence has shown circulating microRNAs (miRNA), particularly miR-371a-3p, to be a more sensitive biomarker, elevated across all MGCT subtypes except teratoma. However, studies to date have been retrospective or non-randomized. If confirmed in prospective clinical trials, circulating miRNA may have the potential to become a universal MGCT biomarker, aiding in diagnosis, prognostication, relapse detection, and prediction of viable disease after chemotherapy. One of the key objectives of AGCT1531 is to test the performance characteristics of circulating miRNA in children, adolescents, and young adults (AYAs) with low-risk and standard-risk MGCTs. AGCT1531 is unique among MGCT trials for including patients across all ages, genders, sites, histologies, and treatments. Methods: AGCT1531 is a prospective clinical trial sponsored by the Children’s Oncology Group (COG), co-designed with United Kingdom, Japan, and India, and supported by all NCTN groups. It has three strata for low-risk tumors, defined as stage I tumors treated with surgery followed by active surveillance: non-seminomatous tumors of any site; testis seminomas; and ovarian immature teratomas. Patients of any age are eligible. Target accruals are 432, 277, and 212 patients, respectively. Key endpoints include overall and event-free survival and longitudinal measurements of circulating miRNA. Serum is collected at intervals aligned with NCCN follow-up guidelines to minimize testing burden. For patients over 11 years old with stage I non-seminomatous tumors, serum is collected at enrollment, months 4, 8, 12, 18, and 24; and (if applicable) at relapse. The trial also has two strata for standard-risk MGCTs: SR1 for children under age 11 years and SR2 for AYAs age 11-25 years. Target accruals are 518 and 595 patients, respectively. Both strata are randomized trials of cisplatin-based versus carboplatin-based regimens, with carboplatin used at doses higher than those previously tested in adult MGCTs. Serum collection is recommended at enrollment, months 6, 12, 18, 24, and (if applicable) at relapse. AGCT1531 was activated in August 2017. The low-risk seminoma stratum was added on November 2021. The trial is currently open at 466 sites across seven countries. For adults with testicular GCTs, data from AGCT1531 can contribute to joint analyses of parallel trials evaluating circulating miR-371a-3p in this population: SWOG1823, ANZUP1906 (CLIMATE), and ANZUP P3BEP. Together, this suite of trials will help validate the utility of circulating miRNA and set the stage for future investigations where miRNA is used to influence real-time management decisions for patients with MGCTs. Clinical trial information: NCT03067181 .

Adjuvant chemotherapy does not improve outcome in children with ovarian immature teratoma: A comparative analysis of clinical trial data from the Malignant Germ Cell International Consortium.

Surgery is the mainstay of therapy for children with ovarian immature teratoma (IT), whereas adults receive adjuvant chemotherapy, except those with stage-I, grade-1 disease. In Brazil, children with metastatic ovarian IT received postoperative chemotherapy. This practice variation allowed evaluation of the value of chemotherapy, by comparison of Brazilian patients with those in the United States and United Kingdom. From the Malignant Germ Cell International Consortium data commons, data on ovarian IT patients from two recently added Brazilian trials (TCG-99/TCG-2008) were compared with data from US/UK (INT-0106/GC-2) trials. Primary outcome measure was event-free (EFS) and overall survival (OS). Forty-two Brazilian patients were included (stage I: 27, stage II: 4, stage III: 8, stage IV: 3). Twenty-nine patients had surgery alone, whereas 13 patients received postoperative chemotherapy. The EFS and OS for entire cohort was 0.80 (95% CI: 0.64-0.89) and 0.97 (0.84-0.99). There was no difference in relapse risk based on stage, grade, or receipt of chemotherapy. Comparing the Brazilian cohort with 98 patients in US/UK cohort (stage I: 59, stage II: 12, stage III: 27), there was no difference in EFS and OS across all stages, despite 87% of stage II-IV Brazilian patients receiving postoperative chemotherapy compared with only 13% of US/UK patients. The EFS and OS for Brazilian compared with US/UK cohort was stage I: 88% versus 98% (p=.05), stage II-IV EFS: 67% versus 79% (p=.32), stage II-IV OS: 93% versus 97% (p=.44); amongst grade-3 patients, there was no difference in EFS or OS. Addition of postoperative chemotherapy did not improve outcome in children with ovarian IT, even at higher grade or stage, compared with surgery alone.

Peritoneal and Nodal Gliomatosis Mimicking Metastasis on FDG PET/CT in a Patient With Ovarian Immature Teratoma.

Peritoneal and nodal gliomatosis is a rare disease condition characterized by implants of mature glial tissue on the peritoneum and lymph nodes. It is typically associated with teratoma and has no adverse effect on prognosis. We present a case of 22-year-old woman who underwent FDG PET/CT for the staging of ovarian immature teratoma. PET/CT revealed mildly increased FDG uptake in the peritoneal cavity and increased FDG uptake in the internal mammary and cardiophrenic angle lymph nodes, which were histopathologically diagnosed as peritoneal and nodal gliomatosis. This case suggests that PET/CT findings of peritoneal and nodal gliomatosis could mimic metastasis.

Rare Case of Ovarian Immature Teratoma with Gliomatosis Peritonei at Follow-Up: Dilemma with F-18 FDG PET CT Imaging

Rare Case of Ovarian Immature Teratoma with Gliomatosis Peritonei at Follow-Up: Dilemma with F-18 FDG PET CT Imaging

Assessment of proliferative activity of immature ovarian teratomas using AgNOR technology

Germ cell tumors arise from the covering stem cells on the surface of the embryonic ovary. They make up 20-30% of all types of ovarian tumors. About 95% are benign and present as mature cystic teratoma, and only 5% are malignant. Malignant germ cell tumors of the ovary represent 2.6% of all malignant tumors of the ovary, in contrast to epithelial tumors of the ovary (95%). A high incidence of ovarian malignant germ cell tumors is observed in the first two decades of life. Determining the prognosis of germ cell tumors of the ovary is a complex and problematic issue, and according to the existing literature, various methods are used to determine a more accurate classification of cases. One of them can be used AgNOR staining, which is called one of the means of proliferation assessment in the case of different tumors, as well as in the differentiation of dysplasias and benign and malignant processes. According to our research, it is used to evaluate proliferative activity during different histological differentiation of immature teratomas.

Role of Adjuvant Chemotherapy in Stage I Pure Ovarian Immature Teratoma: A Systematic Review and Meta-Analysis

To determine the role of adjuvant chemotherapy in stage IA G2-3 and stage IB-IC pure ovarian immature teratoma (POIT), we performed a systematic review and meta-analysis by searching PubMed, Embase, Cochrane library, Web of Science, and ClinicalTrials.gov. Randomized controlled trials or cohort studies on stage IA G2-G3 or stage IB-IC POIT between 1 January 1970 and 15 December 2022 were enrolled. The recurrence rate and mortality rate were the primary outcomes, and subgroup analysis based on the tumor stage and grade was also conducted. In total, 15 studies with 707 patients were included. Compared with surveillance, adjuvant chemotherapy significantly decreased the mortality rate (RR 0.31, 95% CI 0.11-0.88, p = 0.03), but not recurrence (RR 0.74, 95% CI 0.39-1.42, p = 0.37), in the overall population. Subgroup analysis showed no statistical difference in the recurrence rate and mortality rate between patients who received adjuvant chemotherapy and surveillance in pediatric POIT, stage IA G2-3 POIT, stage IB-IC POIT, and stage IA-IC G3 POIT (all with p > 0.05). However, patients who underwent adjuvant chemotherapy appeared to have a lower risk of both recurrence (RR 0.17, 95% CI 0.03-0.83, p = 0.03) and death (RR 0.04, 95% CI 0.00-1.00, p = 0.05) in adult POIT. Adjuvant chemotherapy significantly decreased the mortality rate in patients with stage I POIT and lowered the risk of recurrence in the adult subgroup. Surveillance administered in stage I POIT over IA G1 should be cautious, especially in adult patients.

Characterization of immature ovarian teratomas through single-cell transcriptome.

Immature ovarian teratomas are a type of malignant germ cell tumor composed of complicated cell types and are characterized by pathological features of immature neuroectodermal tubules/rosettes. However, there is a lack of understanding of patient-derived immature ovarian teratomas (PDT) at the single cell level. Moreover, whether stem cell lines derived from immature teratomas (CDT) can be used as models for research on PDT remains to be elucidated. Single-cell RNA sequencing (scRNA-seq) and subsequent bioinformatic analysis was performed on three patient-derived immature ovarian teratomas (PDT) samples to reveal the heterogeneity, evolution trajectory, and cell communication within the tumor microenvironment of PDT. Validations were conducted in additional seven samples through multiplex immunofluorescence. A total of qualified 22,153 cells were obtained and divided into 28 clusters, which can match to the scRNA-seq annotation of CDT as well as human fetal Cell Atlas, but with higher heterogeneity and more prolific cell-cell crosstalk. Radial glia cells (tagged by SOX2) and immature neuron (tagged by DCX) exhibited mutually exclusive expression and differentiated along distinct evolutionary trajectory from cycling neural progenitors. Proportions of these neuroectodermal cell subtypes may play important roles in PDT through contributing to the internal heterogeneity of PDTs. Moreover, the immune cells in PDTs were infiltrated rather than teratoma-derived, with more abundant macrophage in immature neuron than those in radial glia cells, and the infiltrated macrophage subtypes (i.e., M1 and M2) were significantly correlated to clinical grade. Overall, suppressed evolution process and transcriptome regulation in neuroectodermal cells, reduced cell-cell crosstalk, higher M1/M2 proportion ratio, and enhanced T cell effects in tumor microenvironment are enriched in patients with favorable prognosis. This study provides a comprehensive profile of PDT at the single cell level, shedding light on the heterogeneity and evolution of neuroectodermal cells within PDTs and the role of immune cells within the tumor microenvironment. Also, our findings highlight the potential usage of CDTs as a model for research on PDT.

Mature and immature ovarian teratomas share methylation profiles of imprinted genes: a MS-MLPA analysis.

Immature teratomas are a subset of ovarian teratomas, and the pathogenic relationship between mature and immature ovarian teratomas is unclear. Mature ovarian teratomas are parthenogenetic tumors that arise from a single oocyte/ovum, whereas the origin of immature ovarian teratomas has not been extensively investigated. Since parthenogenetic tumors contain only maternal genomes, genome imprinting in these tumors usually follows a maternal pattern. DNA methylation is among the most important mechanisms of genome imprinting. Therefore, we analyzed the methylation profile of imprinted genes by performing methylation-specific multiplex ligation-dependent probe amplification (MS-MLPA) of 25 imprinting control regions (ICRs) in 10 imprinted genes/gene clusters from formalin-fixed, paraffin-embedded samples obtained from 4 immature ovarian teratomas, 8 mature ovarian teratomas, and 4 ovarian yolk sac tumors (YSTs). Both the immature and mature components showed similar methylation levels in each ICR in immature teratomas. Overall, immature ovarian teratomas showed maternal methylation patterns of imprinted genes in concordance with their parthenogenetic origin. However, they also showed aberrant methylation levels in a few imprinted genes, suggesting that genome imprinting in immature teratomas may partially differ from that in mature teratomas. Microscopic foci of YST were seen in one immature teratoma; the YST component also showed a maternal methylation pattern, unlike the pure YSTs that showed irregular patterns. Thus, teratoma-associated YST and pure YST may have different pathogenic mechanisms.

Anti-N-methyl-D-Aspartate Receptor Encephalitis

Background: Anti-N-methyl-D-aspartate receptor (anti-NMDAR) encephalitis is an auto-immune encephalitis with prominent neuropsychiatric manifestations that may be paraneoplastic. Clinical Description: A teenage girl presented with an acute illness of 4 days with symptoms of generalized weakness of all four limbs, behavioral abnormalities, and a generalized convulsion. On examination, the child was hemodynamically stable and disoriented to time, place, or person. There was the loss of recent memory. The remaining neurological and systemic examination was normal. The differential diagnoses considered were toxic or metabolic encephalopathy, neurological Wilson's disease, acute intermittent porphyria, autoimmune encephalitis, and neuropsychiatric systemic lupus erythematosus. Investigations were planned for the causes that could not be excluded by history, examination, and baseline investigations. Salient reports were normal brain magnetic resonance imaging (MRI), nonspecific electroencephalogram abnormalities, and absence of pleocytosis and biochemical abnormalities but positive anti-NMDAR antibodies in the cerebrospinal fluid. A right adnexal cystic solid mass was identified in the abdominal ultrasound with the radiological appearance of an ovarian teratoma or germ cell tumor on MRI. Alpha-fetoprotein levels were raised. Management: The patient underwent right salpingo-oophorectomy. The histopathological diagnosis was an immature ovarian teratoma. The patient received first-line and then second-line immunotherapy (when there was no response), as well as chemotherapy. Signs of improvement appear after 6 weeks, with complete recovery within 6 months. Conclusion: Pediatric ovarian teratoma-associated anti-NMDAR encephalitis is rare, but neuropsychiatric symptoms should prompt the clinician to think of this diagnosis in girls. Early treatment is associated with a good prognosis.

Immature Teratoma with Growing Teratoma Syndrome and Gliomatosis Peritonei Coexistence.

Ovarian germ cell tumours constitute 5% of all ovarian cancers. During the natural course and treatment of these tumours , there may be more unusual cases. One of them is gliomatosis peritonei, which is characterised by the spread of glial cells on the peritoneal surfaces, while the other one is growing teratoma syndrome characterised by the rapid growth of benign component and loss or shrinkage of the malignant component in response to systemic chemotherapy during the treatment of germ cell tumours. Herein, we present a case of coexistence of gliomatosis peritonei and growing teratoma syndrome during the treatment of a 29-year female with immature ovarian teratoma. Key Words: Germ cell tumours , Growing teratoma syndrome, Gliomatosis peritonei, Ovaries.