Gliomatosis peritonei: a clinicopathologic and immunohistochemical study of 21 cases

Large ovarian mature teratoma with gliomatosis peritonei in a young female: A case report

Gliomatosis peritonei is an extremely rare condition usually associated with either immature teratoma or, less commonly, mature teratoma. We present a case of a young female with long-standing progressive abdominal distension, who was diagnosed with mature ovarian teratoma with gliomatosis peritonei and gross ascites. The final diagnosis in this case was determined through the correlation of imaging, operative, and histopathological findings. The presence of enhancing peritoneal nodules usually leads to a suspicion of peritoneal carcinomatosis or abdominal tuberculosis, especially in endemic regions; however, gliomatosis peritonei should always be considered in the differential diagnosis, particularly when associated with teratomas. Radiological findings combined with histopathological reports are valuable in reaching the final diagnosis in these cases.

Immature ovarian teratoma with gliomatosis peritonei, paraneoplastic hyponatremia and growing teratoma syndrome: a case report and literature review

Introduction and relevance

Paraneoplastic hyponatremia is often secondary to syndrome of inappropriate antidiuretic hormone secretion (SIADH) by tumour cells. Immature ovarian teratomas (IOT) are uncommon and may present with SIADH.

Case report

A 26-year-old female presented with a 3-month history of abdominal pain and constipation. Imaging identified a mixed solid-cystic right ovarian mass containing fat and peritoneal deposits. Biochemistry showed severe, refractory hyponatremia (117 mmol/l). She underwent diagnostic fertility-preserving right salpingo-oophorectomy and resection of peritoneal nodules with the aim to achieve symptom control and hyponatraemia resolution. Pathology revealed a FIGO Stage 2 Grade 2 IOT with extensive benign peritoneal gliomatosis. Initial management was conservative. After 6 months of active follow-up, a rise in AFP, and recurrent hyponatremia supported the decision to administer three cycles of Bleomycin-Etoposide-Cisplatin chemotherapy. One month later, given radiological disease progression despite satisfactory biomarker response, cytoreductive surgery with complete macroscopic resection was performed. Pathology consisted solely of peritoneal mature glial elements: a growing teratoma syndrome (GTS). The patient remains disease-free after 2 years of surveillance.

Clinical discussion

Specimen histological assessment from the patient's initial surgery showed immature neuroectodermal tubules, which are thought to be the source of vasopressin secretion. The authors hypothesise that recurrent hyponatremia and rising AFP levels represented postoperative disease relapse. Biochemical response despite radiological disease progression was pathognomonic of a GTS.

Conclusion

Paraneoplastic SIADH secondary to an IOT must be considered in female patients presenting with abdominal symptoms and hyponatremia. Management requires a multidisciplinary approach. Serum electrolytes are useful surveillance biomarkers supplementary to tumour markers.

Ovarian Teratoma Presenting With Gliomatosis Peritonei and a Melange of Symptoms Mimicking Ovarian Cancer in a Paediatric Patient

Gliomatosis peritonei (GP) is a rare condition characterised by mature glial nodules that implant in the peritoneum, lymph nodes, or omentum. GP is typically associated with mature or immature ovarian teratomas and usually affects adolescent females. Although neuroglia may be a standard feature of mature ovarian teratomas, widespread peritoneal glial nodules, ascites, and pleural effusion are rare, particularly in the paediatric population. We report a case of a giant left mature ovarian teratoma associated with GP and omental splenunculus in a 12-year-old female who presented with constipation, an adnexal mass, ascites, pleural effusion, and elevated CA-125 levels. The patient successfully underwent fertility-sparing surgery in the form of a left salpingo-oophorectomy, omentectomy, and resection of peritoneal glial deposits. In light of the current scarcity of data on this clinical entity in the literature, we hope to raise awareness of this rare presentation of mature ovarian teratoma, the challenges associated with preoperative diagnosis, and the impact of fertility-sparing surgery on potential oncological and reproductive outcomes in a paediatric patient.

Ovarian Immature Teratoma With Nodal Gliomatosis: A Case Report and Literature Review

Gliomatosis involving lymph nodes (nodal gliomatosis) is rarely encountered in association with an ovarian teratoma, with 12 cases previously reported. We report this rare occurrence in a 23-yr-old female with an ovarian immature teratoma. The ovary contained a grade 3 immature teratoma, with immature neuroepithelium. A subcapsular liver mass contained metastatic immature teratoma with neuroepithelium. The omentum and peritoneum contained mature glial tissue, consistent with gliomatosis peritonei with no evidence of immature elements. One pelvic lymph node contained multiple nodules of mature glial tissue, diffusely positive for glial fibrillary acidic protein, in keeping with nodal gliomatosis. In reporting this case, we review prior reports of nodal gliomatosis.

Benign and Malignant Ovarian Teratomas: Multimodality Imaging Findings With Histopathologic Correlation

ABSTRACT

The purpose of this article is to provide a comprehensive review of the imaging findings along with histopathologic correlation of mature (benign) teratomas and malignant ovarian teratomas, which include both immature teratomas and malignant degeneration of mature teratomas. The radiologist's ability to provide an accurate diagnosis plays an essential role in guiding the interdisciplinary care of patients with malignant teratomas and improving their outcomes.

Germ Cell Tumors of the Ovary: A Review

Ovarian germ cell tumors are a diverse group of benign and malignant neoplasms that occur in a wide age range, but with a predilection for younger age group. The majority are represented by the frequently encountered mature cystic teratomas. Malignant germ cell tumors are uncommon, and in some cases have a characteristic clinical presentation. However, from a histologic standpoint these tumors can sometimes be challenging to diagnose due to overlapping morphology with epithelial, and in some cases sex cord tumors. In these cases, a panel of immunohistochemical stains often facilitates the correct diagnosis. This review article discusses the clinicopathologic findings and pertinent ancillary studies of both common and uncommon germ cell tumors of the ovary.

Primary immature teratoma in the liver with growing teratoma syndrome and gliomatosis peritonei: a rare case report

Background

Primary liver immature teratoma is extremely rare and only 4 cases have been reported, let alone with growing teratoma syndrome (GTS) and/or gliomatosis peritonei (GP).

Case presentation

Here, we report a case of a 44-year-old female presenting with progressive abdominal distension and elevated serum alpha fetal protein (AFP) level. CT/MRI scans revealed a large cystic-solid mass in the right lobe of the liver, accompanied with implant or metastasis in the abdominal cavity. Pathologic examination at biopsy suggested immature teratoma. After 4 cycles of chemotherapy, an MRI showed a slight increase in tumor size. Therefore, surgical resection of the right lobe of the liver was performed. The final histological diagnosis was a mature teratoma (tumor size 28 cm × 14 cm × 13 cm), with no residual immature component, and the diagnosis of GTS was considered. The patient continued to receive 2 courses of postoperative chemotherapy. An abdominal CT scan revealed innumerable miliary nodules in bilateral adnexal areas 2 months after surgery. Histologically, large numbers of mature glia were observed, supporting the diagnosis of GP.

Conclusions

We report for the first time a case of primary liver immature teratoma with GTS and GP in an adult. Longer follow-up is needed to assess definitive efficacy.

Human chorionic gonadotropin elevation in gliomatosis peritonei complicated with immature teratoma: A case report and review of the literature

RATIONALE

Gliomatosis peritonei (GP) refers to the implantation of glial tissue on the visceral and parietal peritoneal surface, often associated with immature teratoma. It is a rare condition and the pathogenesis is not fully understood. In addition, the indistinguishable radiological appearance of immature and mature teratomas, and limited pathology samples make an accurate diagnosis difficult in most cases. More importantly, patients are also at risk of recurrence after surgery. This report aims to describe the process of diagnosis and treatment of GP with immature teratoma.

PATIENT CONCERNS

The patient, a 38-year-old woman presented with GP complicated with immature teratoma after laparoscopic ovarian cyst excision.

DIAGNOSES

On physical examination, a 15 cm-pelvic mass, with poor mobility, was palpated. And tumor marker demonstrated a moderate increase in α-fetoprotein and carbohydrate antigen 125. We suspected malignancy according to the comprehensive preoperative evaluation, the postoperative pathology revealed an immature teratoma of the left ovary and complicated with gliomatosis peritonei. Three months after the second surgery, possible recurrence of immature teratoma was considered and the patient underwent the third laparotomy. But the postoperative pathology indicated mature teratoma and mature glial components in the pelvic lesions.

INTERVENTIONS AND OUTCOME

The patient underwent 2 more surgical resections after the initial resection and 3 cycles of bleomycin, etoposide, and cisplatin regimen chemotherapy. She was regularly followed up in the outpatient after surgery, and no recurrence has been reported in the pelvic cavity till date.

LESSON

The case illuminated that the primary diagnosis of GP complicated with immature teratoma is critical but highly challenging for both gynecologists and pathologists and more attention should be paid to "GP complicated with immature cystic teratoma" patients to avoid inappropriate treatment.

Aggressive Gliomatosis Peritonei Arising from Ovarian Mature Teratoma with NF1 Mutation: A Case Report and Literature Review

Background

GP arising from ovarian mature teratoma is a rare disease, and no confirmed pathogenesis signature genes are reported. The progress of GP is seen as relatively slow. Rare aggressive GP cases with poor prognosis were reported and no guidelines to follow for treatment.

Case Presentation

Herein, we report a 17-year-old girl with a 3-year-history of GP arising from ovarian mature teratoma. Surgeries and drug therapy were used to treat the aggressively growing tumour. Genetic profiling revealed the pathogenic mutation with potential therapeutic approaches. We firstly reported the NF1 mutations in GP secondary to teratomas and may cause bad prognosis.

Conclusion

GP arising from ovarian mature teratoma is rare; we found NF1 mutation could be the trigger of GP. The study may provide new insights into a better understanding of this rare disease.

Gliomatosis Peritonei and Its Relation to Teratoma: Role of Imaging and Histological Aspects

Gliomatosis peritonei (GP) is a rare disease, usually associated with immature ovarian teratoma. GP may be rarely associated with mature ovarian teratoma. GP is composed of mature glial tissue elements, which histopathological examination can further confirm. Benign glial implants usually involve the omentum, peritoneum and lymph nodes. Many benign and malignant peritoneal diseases may mimic GP on clinical examination. GP may be confused with peritoneal carcinomatosis on computed tomography (CT) scan. A microscopic examination from peritoneal mass biopsy helps to rule out differential diagnosis. GP consists of mature glial tissue and is regarded as grade 0 according to the WHO grading of immature teratoma (IT). GP corresponds to a good prognosis with occasional cases showing malignant evolution.

Growing Teratoma Syndrome with Synchronous Gliomatosis Peritonei during Chemotherapy in Ovarian Immature Teratoma: A Case Report and Literature Review

Coexistent growing teratoma syndrome (GTS) and gliomatosis peritonei (GP) arising during chemotherapy of ovarian immature teratoma (IMT) is extremely rare and can be misdiagnosed as recurrent or progressive disease. We present a 33-year-old woman diagnosed with GTS with synchronous GP during chemotherapy of IMT. She underwent ovarian cystectomy due to ovarian immature teratoma and chemotherapy were administered. The α-fetoprotein (AFP) concentration decreased from 28.7 ng/mL to normal after the second cycle. Four days after the third cycle of chemotherapy, ultrasound and CT revealed an 8-cm mass with negative tumor markers in the pouch of Douglas. An exploratory laparotomy was conducted, and a smooth round cystic-solid 8-cm mass was noted in the pouch of Douglas. Extensive peritoneal seeding glial nodules were also observed on the surface of the uterus, peritoneum, and omentum. The patient underwent a partial omentectomy, intact resection of the tumor, and resection of most of the glial nodules. Postoperative pathology demonstrated a pure mature cystic teratoma component in the mass, as well as diffuse GP involving the uterine serosa, peritoneum, and omentum; this diagnosis of GTS with synchorous GP should be considered in IMT patients with mass newly identified during chemotherapy while tumor markers are normal after treatment.

Growing Teratoma Syndrome and Gliomatosis Peritonei in a 15-Year-Old Girl With Immature Ovarian Teratoma: Case Report and Review of the Literature

Gliomatosis peritonei (GP) is a rare clinical condition characterized by presence of mature glial cells in the peritoneum. Growing teratoma syndrome (GTS) is described as an uncommon phenomenon that could be related to the incidence of non-seminomatous germ cell tumors. We report a case of a patient treated for immature ovarian teratoma, in whom both GP and GTS were observed, an association to date scarcely described in literature. A 15-year-old girl presented to the emergency department with severe pain in her lower abdomen and right lumbar region. Upon admission, concentration of α-fetoprotein (AFP) was 1500 ng/mL and β-human chorionic gonadotropin (β-hCG) less than 2 ng/mL. A computed tomography (CT) scan of the abdominal cavity and pelvis confirmed the presence of an anomalous mass in the abdominal cavity and pelvis. Initial surgery was performed. Histopathology revealed the presence of immature teratoma with epithelial elements. Normalization of AFP was achieved within 8 weeks. Five months after surgery, a progressive increase in AFP was noted. Magnetic resonance imaging (MRI) and CT scans of the pelvis minor showed local relapse. Evaluation of the remission after 2 blocks of preoperative chemotherapy revealed the presence of a large tumor mass in the pelvis minor, despite normalization of the AFP concentration. After opening the abdominal walls, numerous abnormal white nodules were observed in the peritoneum. Histopathology revealed the presence of mature glial tissue (gliomatosis peritonei). The remaining tumor mass was removed, and histopathology confirmed existence of mature teratoma (growing teratoma syndrome). Postoperative chemotherapy was continued. To date, the patient remains under clinical and laboratory remission. Concomitant incidence of GP and GTS, although rare, should always be taken into consideration in pediatric patients with diagnosis of either condition.

Giant liver teratoma with gliosis peritonei treated by right extended hepatectomy: Overview and case report

Germ cell tumors (GCTs) are considered as extragonadal if there is no evidence of a primary tumor in the testes or ovaries. GCTs can be classified as seminomas, non-seminomatous, mature teratomas, and immature teratomas based upon histology. Mature teratomas are generally found in prepuberal children. Less than 1% of them have been reported in the gastrointestinal tract and liver. Liver teratomas are extremely rare. There are only 11 cases reported in adults up to 2018. Isolated liver metastasis of ovarian teratoma is also very rare. We present a case of a late metachronous recurrence of liver cystic teratoma with gliosis peritonei in a female adult treated by a right extended hepatectomy along with a literature review.

Extratesticular gliomatosis peritonei after mesenteric teratoma: a case report and literature review

Mesenteric teratoma is a rare extragonadal teratoma. Gliomatosis peritonei (GP) is mature glial tissue implanted into the peritoneum's surface and is mainly accompanied by ovarian teratoma. Only a few cases of gliomatosis have occurred in the extraperitoneum. We present a rare case of a 3-year-old boy who presented with extratesticular GP after excision of an immature mesenteric teratoma at 2 months old. After the extratesticular mass was excised, we found ductile tissue on the surface of the terminal spermatic cord and epididymis. Some ductile tissue of the epididymis was removed and sent to a laboratory for a pathological examination. The mass and the ductile tissue of the epididymis had a hard consistency. The pathological diagnosis was extratesticular gliomatosis. Complete surgical resection of the teratoma and GP is helpful for identifying the presence of malignant lesions and for preventing malignant transformation. However, characteristics of GP lesions are extensive and they are difficult to completely remove. Moreover, GP is usually benign. Therefore, the residual GP tissue was not completely removed in our case. The child is still in good health, but requires lifelong follow-up. In conclusion, we report our experience of a rare case of extraperitoneal GP from an extragonadal teratoma.

Mature ovarian teratoma with gliomatosis peritonei: A rare case report

Gliomatosis peritonei (GP) is rarely observed along with mature ovarian teratoma. However, it is important to recognize the benign nature of GP when associated with mature ovarian teratoma. Treatment for primary tumor and long-term follow-up is vital.

Cancer Informatics for Cancer Centers: Scientific Drivers for Informatics, Data Science, and Care in Pediatric, Adolescent, and Young Adult Cancer

Cancer Informatics for Cancer Centers (CI4CC) is a grassroots, nonprofit 501c3 organization intended to provide a focused national forum for engagement of senior cancer informatics leaders, primarily aimed at academic cancer centers anywhere in the world but with a special emphasis on the 70 National Cancer Institute-funded cancer centers. This consortium has regularly held topic-focused biannual face-to-face symposiums. These meetings are a place to review cancer informatics and data science priorities and initiatives, providing a forum for discussion of the strategic and pragmatic issues that we faced at our respective institutions and cancer centers. Here, we provide meeting highlights from the latest CI4CC Symposium, which was delayed from its original April 2020 schedule because of the COVID-19 pandemic and held virtually over three days (September 24, October 1, and October 8) in the fall of 2020. In addition to the content presented, we found that holding this event virtually once a week for 6 hours was a great way to keep the kind of deep engagement that a face-to-face meeting engenders. This is the second such publication of CI4CC Symposium highlights, the first covering the meeting that took place in Napa, California, from October 14-16, 2019. We conclude with some thoughts about using data science to learn from every child with cancer, focusing on emerging activities of the National Cancer Institute's Childhood Cancer Data Initiative.

PET/CT Variants and Pitfalls in Gynecological Cancers

The role of hybrid imaging with 2-[18F] flourodeoxyglucose (FDG) positron emission tomography and computed tomography (PET/CT) is continuously evolving and now considered standard practice in evaluation of disease stage, treatment response, recurrent disease and follow-up for numerous primary malignancies. In gynecological malignancies FDG PET/CT plays an important role, not only in the assessment of disease in the pre-and post-therapy setting, but also in radiation therapy (RT) planning by defining the metabolically active gross tumor volume (GTV. The glucose analogue radiotracer, FDG, is by far the most utilized radiotracer in PET/CT and is typically seen with high uptake in malignant cells. The radiotracer FDG has a high sensitivity but low specificity for malignancy, as benign processes with an inflammatory response for example infection, are also FDG-avid. In the evaluation of the female pelvic region an awareness of potential confounding factors in the interpretation of FDG is essential as variations of FDG uptake occur in accordance with the menstrual cycle and the menopausal state. Incidental imaging findings in the female genital can pose differential diagnostic challenges as false-positive and false-negative findings in benign and malignant processes are not uncommon. Gynecological malignancies continue to pose major public health problems with cervical cancer as the fourth most common cancer in women ranking after breast cancer, colorectal cancer and lung cancer. Familiarity with frequently encountered benign and malignant variants and pitfalls in FDG PET/CT in the female pelvic region can aid the reader in differential diagnostic considerations.

Cancer microenvironment and genomics: evolution in process

Cancer heterogeneity is a result of genetic mutations within the cancer cells. Their proliferation is not only driven by autocrine functions but also under the influence of cancer microenvironment, which consists of normal stromal cells such as infiltrating immune cells, cancer-associated fibroblasts, endothelial cells, pericytes, vascular and lymphatic channels. The relationship between cancer cells and cancer microenvironment is a critical one and we are just on the verge to understand it on a molecular level. Cancer microenvironment may serve as a selective force to modulate cancer cells to allow them to evolve into more aggressive clones with ability to invade the lymphatic or vascular channels to spread to regional lymph nodes and distant sites. It is important to understand these steps of cancer evolution within the cancer microenvironment towards invasion so that therapeutic strategies can be developed to control or stop these processes.

Multiregion exome sequencing of ovarian immature teratomas reveals 2N near-diploid genomes, paucity of somatic mutations, and extensive allelic imbalances shared across mature, immature, and disseminated components

Immature teratoma is a subtype of malignant germ cell tumor of the ovary that occurs most commonly in the first three decades of life, frequently with bilateral ovarian disease. Despite being the second most common malignant germ cell tumor of the ovary, little is known about its genetic underpinnings. Here we performed multiregion whole-exome sequencing to interrogate the genetic zygosity, clonal relationship, DNA copy number, and mutational status of 52 pathologically distinct tumor components from ten females with ovarian immature teratomas, with bilateral tumors present in five cases and peritoneal dissemination in seven cases. We found that ovarian immature teratomas are genetically characterized by 2N near-diploid genomes with extensive loss of heterozygosity and an absence of genes harboring recurrent somatic mutations or known oncogenic variants. All components within a single ovarian tumor (immature teratoma, mature teratoma with different histologic patterns of differentiation, and yolk sac tumor) were found to harbor an identical pattern of loss of heterozygosity across the genome, indicating a shared clonal origin. In contrast, the four analyzed bilateral teratomas showed distinct patterns of zygosity changes in the right versus left sided tumors, indicating independent clonal origins. All disseminated teratoma components within the peritoneum (including gliomatosis peritonei) shared a clonal pattern of loss of heterozygosity with either the right or left primary ovarian tumor. The observed genomic loss of heterozygosity patterns indicate that diverse meiotic errors contribute to the formation of ovarian immature teratomas, with 11 out of the 15 genetically distinct clones determined to result from nondisjunction errors during meiosis I or II. Overall, these findings suggest that copy-neutral loss of heterozygosity resulting from meiotic abnormalities may be sufficient to generate ovarian immature teratomas from germ cells.

Ovarian germ cell tumour classification: views from the testis

The classification of ovarian germ cell tumours has remained unchanged for many years, while there have been considerable changes in the testicular classification. In recent years there has been concern about the overtreatment of clinical stage 1 testicular germ cell tumours with increasing use of surveillance for low-risk disease. We outline here the current classification of germ cell tumours of the ovary with particular regard to treatment and outcome and highlight some areas which may cause confusion, particularly pertaining to immature teratomas and mixed germ cell tumours. We suggest that some minor changes to the classification, evidenced by a recent retrospective series by some of the authors, may lead to less adjuvant chemotherapy for immature teratomas and may obviate the need for the grading of immature teratomas, by aligning with testicular experience in pure post-pubertal teratomas. Adoption of this will require retrospective and prospective re-evaluation, but may avoid long-term patient morbidity.

Germ Cell Tumors of the Female Genital Tract

Ovarian germ cell tumors are a histologically diverse group of neoplasms with a common origin in the primitive germ cell. The vast majority are represented by mature cystic teratoma. In the minority are malignant germ cell tumors including immature teratoma, dysgerminoma, yolk sac tumor, embryonal cell carcinoma, and choriocarcinoma. This article reviews the histologic and immunohistochemical features of the most common ovarian germ cell tumors. The differential diagnoses for each are discussed.

Comparative RNA-seq analysis aids in diagnosis of a rare pediatric tumor

Gliomatosis peritonei is a rare pathologic finding that is associated with ovarian teratomas and malignant mixed germ cell tumors. The occurrence of gliomatosis as a mature glial implant can impart an improved prognosis to patients with immature ovarian teratoma, making prompt and accurate diagnosis important. We describe a case of recurrent immature teratoma in a 10-yr-old female patient, in which comparative analysis of the RNA sequencing gene expression data from the patient's tumor was used effectively to aid in the diagnosis of gliomatosis peritonei.

Derivation of neural stem cells from human teratomas

Human teratoma is a germ cell tumor that contains normal tissues (e.g., hair, skin or cartilage) differentiated from embryonal germ layers. Because of the feature of this tumor, we hypothesized that human teratomas contain multipotent stem cells that can develop into various non-cancerous normal tissues. In this study, we cultured neurospheres originally derived from a human infantile teratoma tissue, and the sphere cells were found to possess the characteristics of neural stem cells. Tumor tissues were obtained from an infantile immature teratoma at the time of surgical resection. In the primary cell culture, colonies were formed in two weeks and were individually cultured in serum-free conditioned neural stem cell medium (NSC medium). Colonies changed into spheres and grew in smooth round forms, or attached to the bottom of the dishes and extended processes and filaments around. Sphere cells were dissociated into single cells, and new spheres (secondary spheres) were formed in NSC medium. Cell differentiation was induced by culturing cells in serum-containing medium (differentiation medium), as cells spread and attached to the bottom of dishes and changed form. The expression of Nestin, Sox2, CXCR4, and (stem cell markers), β3-tubulin (a neural marker) GFAP (a glial marker) CNPase, SOX10 (oligodendrocyte markers) and NF-L in cells was analyzed by immunofluorescence and a Q-PCR. Nestin, SOX2, CXCR4 were abundant in both primary and secondary spheres. Neural and glial markers (β3-tubulin and GFAP, respectively) were increased in cells cultured in differentiation medium while stem cell markers were diminished. The oligodendrocyte markers SOX10 and CNPase were also found in both spheres and differentiated cells. In conclusion, spheres with the characteristics of neural stem cells were obtained from the primary culture of a human infantile teratoma. These spheres are considered to have the potential to undergo a natural course of neural development in humans.

Ovarian neoplasms of childhood

Ovarian neoplasms are rare in children. Although usually asymptomatic, they sometimes present with abdominal pain, abdominal distension or palpable mass. The distribution of neoplasms in the pediatric population is different from in adults; benign mature cystic teratoma is the most common ovarian tumor in children. Radiologists should be familiar with the variable sonographic, CT and MRI findings of ovarian neoplasms. Although the less frequently encountered ovarian malignancies cannot be reliably distinguished by imaging alone, it does play an important role in workup. This review discusses the imaging and relevant clinical manifestations of the more commonly encountered pediatric ovarian neoplasms.

Huge ovarian mature cystic teratoma with gliomatosis peritonei and massive ascites in a postmenopausal woman

Teratoma of the ovary is the most frequently encountered germ cell tumor. It usually occurs in young women. Gliomatosis peritonei (GP) is mature neural glial tissue implanted onto the peritoneal surface. We present a case of a mature teratoma accompanied by GP and massive ascites in postmenopausal women. A 54-year-old, G0P0, woman presented in the gynecology outpatient department with abdominal distension for 6 months. Computed tomography scan of the abdomen and pelvis displayed an ovarian mass about 20 cm × 18 cm with peritoneal seeding, ascites, and enlarged paraaortic lymph nodes. A total hysterectomy and bilateral adnexectomy were performed. The pathology showed the left ovary contained a dermoid cyst. The biopsy of the peritoneal nodule displayed glial tissue confirming the diagnosis of GP. The patient remained in good condition 6 months postoperatively. We suggest GP be considered in patients presenting with teratomas and massive ascites. The radiological diagnosis is challenging due to the rarity of GP. Continued follow-up of patients with teratomas and GP is mandatory due to the potential of malignant transformation.

Unusual Imaging Findings Associated with Germ Cell Tumors

Germ cell tumors, because they contain immature and mature elements, can differentiate into different tissue types. They can exhibit unusual imaging features or manifest in a syndromic fashion. The authors describe these features and assign them to one of the following categories: (a) unusual manifestations of metastatic disease (growing teratoma syndrome, choriocarcinoma syndrome, ossified metastases, and gliomatosis peritonei); (b) autoimmune manifestations (sarcoidlike reaction and paraneoplastic syndromes); (c) endocrine syndromes (sex hormone production, struma ovarii, and struma carcinoid); or (d) miscellaneous conditions (ruptured dermoid cyst, squamous cell carcinoma arising from a mature teratoma, Currarino triad, fetus in fetu, pseudo-Meigs syndrome, and pancreatitis). Rare conditions associated with germ cell tumors demonstrate characteristic imaging findings that can help lead to the appropriate diagnosis and management recommendations. When evaluating for potential metastatic disease, alternative benign diagnoses should be considered (eg, growing teratoma syndrome, ossified metastases, ruptured dermoid cyst, gliomatosis peritonei, and sarcoidlike reaction), which may impact management. Germ cell tumors may also lead to life-threatening complications such as extensive hemorrhage from choriocarcinoma metastases or the rupture of mature teratomas, cases in which timely diagnosis is crucial. Autoimmune and endocrine manifestations such as paraneoplastic encephalitis, autoimmune hemolytic anemia, and hyperthyroidism may occur owing to the presence of germ cell tumors and can create a diagnostic dilemma for clinicians. Knowledge of the syndromic and unusual imaging findings associated with germ cell tumors helps guide appropriate management. ^©RSNA, 2019.

The utility of anti-SOX2 antibodies for cancer prediction in patients with paraneoplastic neurological disorders

Antibodies to SOXB1 proteins in patients with paraneoplastic disorders are associated with small-cell lung cancer (SCLC), particularly in Lambert-Eaton myasthenic syndrome (LEMS). We aimed to establish if SOX2 antibodies could be used to identify SCLC and other tumours found in a range of paraneoplastic disorders and controls. SOX2 antibodies were detectable in 61% of patients with LEMS-SCLC, and in other paraneoplastic disorders, such as opsoclonus-myoclonus and paraneoplastic cerebellar degeneration, only when there was an underlying SCLC. SOX2 antibodies are specific (>90%) markers for SCLC, but are rarely found in patients with other tumours, whether neurological symptoms are present or not.

Primary Glial and Neuronal Tumors of the Ovary or Peritoneum: A Clinicopathologic Study of 11 Cases

Primary glial and neuronal tumors of the ovary or peritoneum are rare neuroectodermal-type tumors similar to their counterparts in the central nervous system. We retrospectively reviewed 11 cases. These cases included 4 ependymomas, 6 astrocytic tumors, and 1 neurocytoma. Patients' age ranged from 9 to 50 years (mean, 26 y; median, 24 y). All ependymal tumors with detailed clinical history (n=3) were not associated with any other ovarian neoplasm. In contrast, all astrocytic tumors were associated with immature teratoma (n=4), mature cystic teratoma (n=1), or mixed germ cell tumor (n=1). The neurocytoma arose in association with mature teratomatous components in a patient with a history of treated mixed germ cell tumor. Immunohistochemical staining showed that 7 of 7 ependymal and astrocytic tumors (100%) were positive for glial fibrillary acidic protein, and 2 of 2 ependymomas (100%) were positive for both estrogen and progesterone receptors. The neurocytoma was positive for synaptophysin and negative for S100 protein, glial fibrillary acidic protein, and SALL4. No IDH1-R132H mutation was detected in 2 of 2 (0%) astrocytomas by immunohistochemistry. Next-generation sequencing was performed on additional 2 ependymomas and 2 astrocytomas but detected no mutations in a panel of 50 genes that included IDH1, IDH2, TP53, PIK3CA, EGFR, BRAF, and PTEN. Follow-up information was available for 8 patients, with the follow-up period ranging from 4 to 59 months (mean, 15 mo; median, 8.5 mo), of which 3 had no evidence of disease and 5 were alive with disease. In conclusion, primary glial and neuronal tumors of the ovary can arise independently or in association with other ovarian germ cell tumor components. Pathologists should be aware of these rare tumors and differentiate them from other ovarian neoplasms. Even though an IDH1 or IDH2 mutation is found in the majority of WHO grade II and III astrocytomas, and in secondary glioblastomas arising from them, such mutations were not identified in our series, suggesting that these tumors are molecularly different from their central nervous system counterparts despite their morphologic and immunophenotypic similarities.

18F FDG positron-emission tomography findings of gliomatosis peritonei: A case report and review of the literature

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Gliomatosis peritonei (GP) is a rare benign complication of ovarian teratomas that does not impact overall survival.

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GP exhibits high 18-F FDG uptake unlike other non-malignant forms of mature teratoma.

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The specific characteristics of GP on functional imaging may be used to follow it with active surveillance in select cases.

Gliomatosis peritonei: a series of eight cases and review of the literature

BACKGROUND

Gliomatosis peritonei (GP) is a rare condition characterized by mature glial tissue implants widespread in the peritoneum. The GP is often associated with ovarian teratoma. However, little is known about the characteristics and prognosis of GP. The purpose of this study was to describe the features, treatment, and prognosis of GP. Additionally, we review previously reported cases of GP, summarizing the presently known data.

METHODS

From January 2000 to January 2016, cases of ovarian teratoma and GP treated at Peking Union Medical College Hospital were reviewed. We assessed the pathology, treatments, and outcomes along with prognostic information. Additionally, the literature regarding this clinical condition was also reviewed.

RESULTS

Eight patients met the inclusion criteria. Patients had a median age of 20 (range, 15-25) years. GP was diagnosed as the primary tumor in 6 patients and at a secondary surgery in two patients. The primary ovarian tumor consisted of immature teratoma (n = 7) and mature teratoma (n = 1). Grades of immature ovarian teratoma were 2, grade 1; 3, grade 2; and 2, grade 3. Tumors mean had a size of 20.4 (range, 11-30) cm. The median follow-up time was 60.5 (range, 3-144) months. All cases had conservative surgery and seven of them had macroscopic residual disease postoperatively. During the study period, the eight patients remained alive and asymptomatic. Three patients in the study experienced spontaneous pregnancy. After reviewing the existing literature, a total of 14 patients with nodal gliomatosis were present and 10 of them were alive. According to the literature review, five articles reported more than five cases. Of a total of 67 patients, 60 of them remained alive.

CONCLUSION

The prognosis of immature ovarian teratoma with GP is favorable. Complete resection of GP is often difficult. Residual peritoneal disease in GP can be asymptomatic and quiescent over a long period. A more conservative surgical approach may be carried out in patients with massive peritoneal spread after the presence of metastatic immature elements is excluded. Owing to the risk of recurrence and malignant transformation of GP, a long-term follow-up is necessary for patients with residual peritoneal disease.

Gliomatosis peritonei with bilateral ovarian teratomas: A report of two cases

Gliomatosis peritonei (GP) is characterized by the presence of benign, mature neuroglial implants throughout the peritoneum and is typically accompanied by mature or immature ovarian teratomas. GP is a condition that has only been described relatively recently, with ~100 cases reported in the English literature. The majority of reported cases have focused on the pathology and clinical treatment of the disease; radiological findings are distinct, but the discussion of this is scarce in the literature. The current study presents two cases of GP with bilateral ovarian teratomas and provides a review of the relevant literature, with particular emphasis on the radiological differential diagnosis. The present study reinforces previously reported observations from imaging analysis and suggests that radiological investigation alone cannot sufficiently aid the differentiation of benign glial deposits from diffuse peritoneal malignant seeding. However, radiologists should be familiar with this rare condition in order to provide an accurate diagnosis, particularly in ovarian tumor staging, which may markedly impact the administered treatment. It is recommended that doctors undertake long-term follow-ups in patients presenting with GP due to the potential for malignant transformation.