Sacrococcygeal teratoma: late recurrence warrants long-term surveillance

The Diagnostic Accuracy of Serum Alpha-Fetoprotein Levels in Follow-up for Recurrence of Sacrococcygeal Teratoma; a Nationwide Review of SCT Cases in the Netherlands

BACKGROUND

Serum alpha-fetoprotein (AFP) is often used as tumour marker for recurrent sacrococcygeal teratoma (SCT). We aimed to assess the normal dynamics of serum AFP levels after initial resection and diagnostic accuracy of serum AFP levels the follow-up for recurrence in SCT.

METHODS

This retrospective study included 57 patients treated for SCT in the six pediatric surgical centers in the Netherlands from 1980 to 2018.

MAIN RESULTS

57 patients were included in the study of whom 19 children developed 20 recurrences at a median of 14.0 months after initial resection. No significant difference was found in serum AFP level dynamics between the recurrence and non-recurrence group after initial resection (p = 0.950). Serum AFP levels did not significantly increase before recurrence (p = 0.106) compared to serum AFP levels of children without recurrence at the same time. However, serum AFP levels did significantly increase in malignant recurrences (n = 7) (p = 0.03) compared to patients without recurrence. A cut-off value of 55 μg/L was found to be predictive for recurrent SCT with an Area Under the Curve (AUC) of 0.636 with sensitivity of 50% and specificity of 100%.

CONCLUSION

Dynamics of serum AFP levels are not different between patients with and without recurrence after initial resection of SCT. Serum AFP levels are not predictive for mature or immature recurrent SCT and normal AFP levels do not rule out recurrent SCT. However, serum AFP levels exceeding 55 μg/L can indicate recurrent SCT, especially malignant recurrences.

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.

Laparoscopic transabdominal-sacrococcygeal approach for resection of Altman type III sacrococcygeal teratoma in adult women: A case report

INTRODUCTION

Adult sacrococcygeal teratoma (SCT) is a rare disease that is not easily detected or easily missed, and its treatment is based on surgery, including transabdominal, transsacral, or a combination of both, but there are no clear guidelines for diagnosis and treatment. We share a case of Altman type III SCT in order to provide more reference protocols for the diagnosis and treatment of adult SCT, and more importantly to increase our understanding of different types of SCT cases in adults.

PATIENT CONCERNS

Our patient was a 31-year-old adult woman who underwent complete surgical resection of a cystic mature teratoma of the right ovary 8 years ago and is currently 13 months postpartum without menstruation, usually with a feeling of anal bulge, with symptoms such as constipation.

DIAGNOSIS

We diagnosed SCT by vaginal ultrasonography, computed tomography and magnetic resonance imaging (MRI); benign tumors were considered in the results of serum tumor markers.

INTERVENTIONS

We chose the surgical approach of laparoscopic transabdominal-sacrococcygeal approach to completely remove the patient SCT and coccyx.

OUTCOMES

The location of SCT is concealed and the clinical symptoms are not obvious. Vaginal ultrasonography, CT and MRI can not only improve the diagnostic rate of SCT, but also understand the size and mass of SCT, providing an exact basis for clinicians to select the laparoscopic transabdominal-sacrococcygeal approach.

CONCLUSION

Our sharing increases the reports of rare cases of teratoma with the same histological findings in different organ tissues of the same patient at different times, whether this occurs incidentally requires more case reports and further basic research; in addition, the laparoscopic transabdominal-sacrococcygeal approach is a safe and effective surgical approach for the treatment of Altman type III SCT in adults; finally, this case reminds us that SCT may not affect pregnancy and pregnancy outcomes and provides a reference for the selection of interventions for SCT with pregnancy.

Long-Term Outcomes of Infantile Sacrococcygeal Teratoma: Results from a Multi-Institutional Retrospective Observational Study in Japan

BACKGROUND

Tumor recurrence, anorectal and urinary dysfunction, and lower limb dysfunction after surgery are observed in infantile sacrococcygeal teratoma (SCT). In this paper, a multi-institutional retrospective observational study was conducted to clarify the long-term functional prognosis in Japan.

METHODS

This study was conducted using a paper-based questionnaire distributed to 192 facilities accredited by the Japanese Society of Pediatric Surgeons, covering patients who underwent radical surgery at less than 1 year old and who survived for at least 180 days after birth from 2000 to 2019.

RESULTS

A total of 355 patients were included in this analysis. Altman type was I-II in 248 and type III-IV in 107, and the median maximum tumor diameter was 6.1 (range: 0.6-36.0) cm. There were 269 mature teratomas, 69 immature teratomas, and 10 malignant tumors. Total resection was performed in 325, subtotal or partial resection in 27, and surgical complications were noted in 54. The median postoperative follow-up was 6.6 (0.5-21.7) years. Eighty-three patients (23.4 %) had functional sequelae, including 62 (17.5 %) with anorectal dysfunction, 56 (13.0 %) with urinary dysfunction, and 15 (4.2 %) with lower limb motor dysfunction. Recurrence occurred in 42 (11.8 %) at a median age of 16.8 (1.7-145.1) months old. Risk factors for dysfunction included preterm delivery, a large tumor diameter, Altman type III-IV, incomplete resection, and surgical complications. Risk factors for recurrence included immature teratoma or malignancy, incomplete resection, and surgical complications.

CONCLUSIONS

Postoperative dysfunction was not low at 23.4 %, and 11.8 % of the patients experienced recurrence occurring more than 10 years after surgery, suggesting the need for periodic imaging and tumor markers evaluations in patients with risk factors. It is necessary to establish treatment guidelines for best practice monitoring of the long-term quality of life.

LEVEL OF EVIDENCE

Level II Retrospective Study.

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.

Immature Sacrococcygeal Teratoma: A Case Report and Extensive Review of the Literature

Immature sacrococcygeal teratoma represents a histological form with rapid tumor growth, a risk of premature birth, an enhanced rate of complications, an increased risk of recurrence, and a higher mortality rate than the mature type. Thus, prenatal diagnosis of immature forms would significantly improve the prognosis of these cases. To this end, we performed an extensive literature review on the diagnosis, therapeutic management, and follow-up of immature teratomas. Regarding this medical conduct, we also presented our case. In conclusion, the early identification of immature sacrococcygeal teratomas with or without other associated structural abnormalities and their correct therapeutic approach are basic principles for a favorable evolution of these cases.

Critical elements of pediatrics sacrococcygeal germ cell tumor surgery

Sacrococcygeal teratoma is the most common extragonadal germ cell tumor in the pediatric population, and accounts for approximately 70% of all teratomas in childhood.1,2 They present in two distinct phases, with most cases seen in neonates with large predominately exophytic tumors, often detected in utero on prenatal sonography or at birth. A smaller cohort presents in older infants and children with primarily hidden tumors in the pelvis which have a much higher rate of malignancy. The primary surgical objective is complete tumor resection without compromise to critical structures or function. Herein we outline the critical elements of tumor resection and management of sacrococcygeal germ cell tumors with a focus on the technical aspects of this tumor across a range of presentations.

Management strategy and outcomes of sacrococcygeal teratoma - an Egyptian multicenter experience

OBJECTIVES

Nationwide criteria regarding patients with sacrococcygeal teratoma (SCT) are still lacking in Egypt. We aimed to present a multicenter study regarding the management and outcomes of this tumor to evaluate our national treatment strategy.

METHODS

A retrospective analysis including all patients with SCT who were managed at four major Egyptian centers between 2013 and 2023. Clinical data, surgical approaches, and short- and long-term outcomes were discussed.

RESULTS

The study included 95 patients (74 were females). Antenatal diagnosis was reported in 25% of patients. Seventy-one patients (74.7%) were classified as Altman type I/II. Surgery was performed via a perineal approach in 75 patients, whereas the remaining 20 underwent a combined abdominoperineal approach. Vertical elliptical incision with midline closure was conducted in 51.5% of patients, followed by classic or modified chevron incisions. Benign mature teratoma was detected in 82% of patients. At a median follow-up of 57 months, eight patients (8.5%) had relapsed. The 5-year overall survival (OS) and event-free survival (EFS) of all patients were 94% and 91%, respectively. In the after-care monitoring, 19 patients (20%) had urinary or bowel dysfunctions. Nine of them were managed using medications. Clean intermittent catheterization was practiced in another five patients. The remaining five underwent further surgical interventions.

CONCLUSION

Favorable outcomes were achieved in our country during the last decade. Diverse perineal incisions were performed for resection, and vertical elliptical with midline closure was the commonest. During follow-up, 20% of patients developed urological or bowel dysfunctions that required medical and surgical treatment modalities to improve their quality of life.

Giant sacrococcygeal teratoma in a neonate: illustrative case

BACKGROUND

Sacrococcygeal teratomas (SCTs) are tumors that emerge in the sacrococcygeal area and contain tissue from all three germ layers. SCT affects about 1 in every 35,000–40,000 live births, with malignant transformation becoming more common as the patient gets older. Ultrasound helps in prenatal diagnosis. Surgical resection is the mainstay of treatment.

OBSERVATIONS

A couple gave birth to a neonate with a small mass over his sacral region that progressively increased in size. Diagnostic magnetic resonance imaging was performed, and a diagnosis of giant SCT was established. Complete resection with flap reconstruction was performed. In regular follow-up, he is in a good state of health.

LESSONS

One of the most common tumors in infancy, SCT should be carefully diagnosed. SCT is often confused with neural tube defects such as myelocystocele or myelomeningocele. Complete resection with appropriate reconstruction can ensure better treatment, and close follow-up until adulthood is recommended to keep a close view on its possible recurrence and to improve prognosis. Postoperative complications such as infection, bleeding, and urethral complications should be carefully watched.

Sacrococcygeal teratomas: midline reconstruction improves cosmesis without compromising outcomes

AIM

Several studies have addressed the long-term functional, psychosexual and psychosocial outcomes following sacrococcygeal teratoma (SCT) excision. It is well reported that the classical chevron incision and reconstruction can leave a cosmetically unsatisfactory result; however, there is little in the literature focussed on improving this outcome. In our institution the preference is to perform a midline reconstruction, where possible, this is felt to improve appearance without compromising the oncological or functional outcome. The aim of this study was to evaluate patient-perceived cosmetic outcomes of the midline reconstruction.

METHODS

All patients undergoing surgery for SCT between 2007 and 2020 were included in the study. Patient demographics, operation type, functional outcome and recurrence were all recorded. The primary outcome measure was patient/parent satisfaction with the cosmetic appearance. This was assessed using both qualitative and quantitative methodologies. Following ethical approval parents were asked questions from two existing validated patient outcome questionnaires: "Patient and Observer Scar Assessment Scale" (POSAS) v2.0 and the "Patient Scar Assessment Questionnaire".

RESULTS

Thirty-two patients underwent surgery at our institution for SCT during the study period. Twenty-four had a posterior approach with midline reconstruction, two laparotomy and excision (excluded from this study) and six had a combined approach. Median follow-up was 35 months (8.5-96 months). There were no recurrences. 4/30 (13%) have persistent urological symptoms, and 1/30 (3%) has constipation requiring bowel management. Questionnaires were sent to 26/30 families with a 77% return rate. Median total score was 11 (7.4-17.5) on a 60-point scale (6, as normal skin, 60, worst imaginable scar). Twenty (95%) reported that the scar never affects the child's activities and 15 (71%) said they are "not at all" conscious of the scar.

CONCLUSION

Scars can lead to an array of cosmetic, functional, and psychological consequences and as such consideration needs to be given to scarring following surgery for sacrococcygeal teratomas. This study demonstrates that a midline reconstruction produces a cosmetically favourable outcome. We, therefore, recommend where appropriate a midline reconstruction should be considered for SCT.

Differences in postoperative complications and prognosis of sacrococcygeal teratoma and presacral tumors in Currarino syndrome

Background

While sacrococcygeal teratoma (SCT) is a tumor originating from the tip of the sacrum, presacral tumors are accompanied by Currarino syndrome (CS) and classified as the Altman’s type IV sacrococcygeal tumors. They are quite different in their pathologies despite the similar location. To the best of our knowledge, there are no published reports comparing their prognosis; therefore, we analyzed their postoperative results and long-term prognosis. Twenty patients with SCT, including CS, who were being followed up at the outpatient clinic of the Department of Pediatric Surgery, Miyagi Children's Hospital between 2004 and 2020, were enrolled in the study. Patients were divided into two groups: those who developed SCT without anorectal malformation and sacral dysplasia, and those who developed presacral tumors with anorectal malformation or sacral dysplasia as CS. Patient records were retrospectively reviewed for clinical details, postoperative complications, and long-term prognosis.

Results

Tethered cord syndrome occurred significantly more frequently in the CS group (p = 0.0108). However, no significant differences were observed for malformations other than tethered cord syndrome. Early complications in the CS group were significantly higher than those in the SCT group (p = 0.023); the most common complication was dysuria. Regarding long-term prognosis, 70% of patients in the CS group complained of defecation disorders, which was significantly higher than that in the SCT group (p = 0.0198). Voiding dysfunction was also more common in the CS group.

Conclusions

There were significant differences between SCT and CS regarding the rate of development of tethered cord syndrome, short-term postoperative complications, and long-term prognosis. Thus, they are different diseases with the only commonality being the presence of a sacrococcygeal tumor. Furthermore, this study indicated that the background and prognosis of the two conditions were also quite different.

Sacrococcygeal Teratoma : A Tumor at the Center of Embryogenesis

Sacrococcygeal teratoma (SCT) is an extragonadal germ cell tumor (GCT) that develops in the fetal and neonatal periods. SCT is a type I GCT in which only teratoma and yolk sac tumors arise from extragonadal sites. SCT is the most common type I GCT and is believed to originate through epigenetic reprogramming of early primordial germ cells migrating from the yolk sac to the gonadal ridges. Fetal SCT diagnosed in utero presents many obstetrical problems. For high-risk fetuses, fetal interventions (devascularization and debulking) are under development. Most patients with SCT are operated on after birth. Complete surgical resection is the key for tumor control, and the anatomical location of the tumor determines the surgical approaches. Incomplete resection and malignant histology are risk factors for recurrence. Approximately 10-15% of patients have a tumor recurrence, which is frequently of malignant histology. Long-term surveillance with monitoring of serum alpha fetoprotein and magnetic resonance imaging is required. Survivors of SCT may suffer anorectal, urological, and sexual sequelae later in their life, and comprehensive evaluation and care are required.

Malignant sacrococcygeal germ cell tumors in children in Taiwan: A retrospective single-center case series

Although the incidence of malignant sacrococcygeal germ cell tumors (MSGCTs) is high in the East Asian countries, information about MSGCTs from this region is limited. This report aimed to analyze the data of children with MSGCTs in a single medical center in Taiwan.Patients aged 18 years or younger with primary MSGCTs or malignant recurrence of a sacrococcygeal teratoma who underwent surgery during the neonatal period between January 1999 and December 2016 were identified from the Linkou Chang Gung Cancer Center registry. The clinical features, laboratory data, and treatment outcomes were reviewed.Fifteen children (1 man and 15 women) with MSGCTs were identified. Sacrococcygeal tumors were present at birth in 7 patients. All patients presented with a bulging mass at the buttock region and they had normal alpha-fetoprotein levels at the time of diagnosis. They underwent primary excision of the tumor. Immature teratoma was histologically diagnosed in 5 neonates, and mature teratoma in 2. Only 1 patient with grade 3 immature teratoma received adjuvant chemotherapy. Two patients with mature teratoma developed malignant recurrence 1.6 and 2.1 years later, respectively. Eight patients were diagnosed with MSGCTs after the neonatal period. The common presenting symptoms included buttock asymmetry (37.5%), abdominal distension (25%), and constipation (12.5%). Seven patients had elevated alpha-fetoprotein levels for their age. They were administered neoadjuvant chemotherapy followed by tumor excision if a residual tumor was present. The histology of the excised tumor included mature teratoma (66.7%) and necrosis (33.3%). One patient with a normal alpha-fetoprotein level underwent primary tumor excision followed by adjuvant chemotherapy. Grade 2 immature teratoma with embryonal carcinoma was diagnosed histologically. Among the 15 patients with MSGCTs, 3 had a recurrence (at age of 2.1, 0.5, and 2.4 years, respectively) and 1 died (at age of 6.1 years) of disease progression. The 5-year overall and event-free survival rates were 90% and 80%, respectively.Children with MSGCTs had good overall prognoses in this case series. For those with sacrococcygeal mature teratoma or low-grade immature teratoma in the neonatal period, we recommend close follow-up for at least 3 years after surgery to detect malignant recurrence.

Sacrococcygeal teratoma in one twin: a case report and literature review

Background

Sacrococcygeal teratoma is one of the most common congenital tumors in newborns and infancy. The incidence is 1 per 20,000–40,000 live births. Ultrasonography is an optimal method for prenatal screening and diagnosis of fetal sacrococcygeal teratoma. MRI can be used to assist in the diagnosis. However, sacrococcygeal teratoma in the twin pregnancy is rare.

Case presentation

We reported a case of one twin with sacrococcygeal teratoma in dichorionic-diamniotic twin pregnancy.One twin with sacrococcygeal teratoma was diagnosed at the second trimester by ultrasonic examination and another twin was normal. A regular and careful antenatal care was conducted by the multidisciplinary team. The parents refused to perform the fetal MRI and examine the chromosome of both twin.At 37 + 1 of gestation, planned cesarean section was performed. The healthy male co-twin (twin A) weighed 2880 g.The male twin with SCT (twin B) weighed 2900 g, complying with 6 × 3 × 3 cm cystic and solid mass in sacrococcygeal region. At four days of age twin B underwent excisional surgery of the sacrococcygeal teratoma and coccyx and discharged 7 days after surgery. The mother and both babies were followed up and are all in good health until now.

Conclusion(s)

Sacrococcygeal teratoma in twin pregnancy is rare. Early antenatal diagnosis is important. Once the sacrococcygeal teratoma is diagnosed, clinicians should be aware of the associated maternal and fetal complications. Expecting parents should be counseled by the multidisciplinary team about the management and prognosis of the STC twin and co-twin. Prompt surgical excision of the sacrococcygeal teratoma after birth should be suggested.

Malignant recurrence after mature Sacrococcygeal teratoma: A meta-analysis and review of the literature

BACKGROUND AND AIMS

Sacrococcygeal teratoma (SCT) is a rare extragonadal germ cell tumour mostly diagnosed during infancy and early childhood. Neonatal SCTs are mostly mature, but can also contain immature and/or malignant components. Recurrence of an SCT alters prognosis, especially when it is malignant, of which its mechanism is not yet fully understood. This study is a review and meta-analysis of the literature on malignant recurrences after an initially mature SCT.

METHODS

A literature search was performed to identify studies describing children with SCT and presenting specific information on histology of the initial tumour as well as the recurrence. Random effect models for mature recurrence and malignant recurrence after an initially mature SCT were employed to pool study-specific percentages in order to estimate an overall percentage and its associated 95 % confidence intervals (CI). Inverse variance method, which gives more weight to larger studies, was used to pool outcomes for the different studies.

RESULTS

A total of 22 articles, comprising 1516 patients with SCT, were included in the meta-analysis. The pooled proportions of mature and malignant recurrences after mature SCT were 3 % (95 % CI 1-4 %) and 5% (95 % CI 3-6 %), respectively. Fifty-seven (56 %) of a total of 102 recurrences after resection of an initially mature SCT were malignant, mostly yolk sac tumour (YST). Many recurrences occurred within 1-6 years, however some occurred as long as 20 years after initial diagnosis.

CONCLUSIONS

A substantial number of recurrences of mature SCT present as a malignant tumour. Overlooking malignant components on initial pathological evaluation and the progression of mature SCT cells to malignant cells may play a role. Treatment of mature SCTs with resection alone requires thorough follow-up of at least 6 years. Future research is needed to determine whether SCTs with malignant microfoci should be treated or followed-up differently from mature or immature SCTs. In addition, the value of serum biomarkers in follow-up after SCT needs to be further evaluated.

Diagnostic accuracy of serum alpha-fetoprotein levels in diagnosing recurrent sacrococcygeal teratoma: A systematic review

BACKGROUND

The incidence of children developing recurrent sacrococcygeal teratoma (SCT) is 2-35%. Serum alpha-fetoprotein (AFP) is often used as a tumor marker for (malignant) recurrences of SCT and could potentially be used during routine follow-up after SCT resection. However, the diagnostic accuracy of serum AFP levels during follow-up has not been well established. Therefore, we aimed to systematically review the diagnostic accuracy of serum AFP levels in recurrent SCT.

METHODS

We queried Search Premier, COCHRANE Library, EMCARE, EMBASE, PubMed, ScienceDirect and Web of Science databases to identify studies regarding patients with SCT with follow-up using serum AFP levels postoperative. We estimated sensitivity and specificity of serum AFP levels.

RESULTS

Fifteen studies (613 patients, 121 recurrences) were included and these mainly described serum AFP levels in patients with recurrent SCT (n = 111); 83 (75%) patients with recurrent SCT had elevated serum AFP levels. A subgroup analysis of articles that measured serum AFP levels in all patients (n = 6, 136 patients, 14 recurrences) showed a sensitivity and specificity of 79% and 95%, respectively. The sensitivity of AFP levels to detect malignant recurrence was 96%.

CONCLUSION

Diagnostic accuracy of serum AFP levels to detect recurrent SCT seems promising, though sensitivity could be overestimated since serum AFP levels are mainly described in patients with elevated AFP levels or at recurrent SCT. Furthermore, serum AFP levels could be helpful to detect malignant recurrences.

TYPE OF STUDY

Systematic review of level 2-4 studies.

LEVEL OF EVIDENCE

Level 2-4 (mostly level 2).

Imaging in pediatric ovarian tumors

The spectrum of ovarian tumors in the pediatric population differs significantly from that in adults. Germ cell tumors are the predominant class of ovarian tumors in children, whereas epithelial tumors are the most common in adults. Ultrasonography is the modality of choice for the initial evaluation of pediatric ovarian tumors. Determining the diagnosis based on imaging may prove difficult, and combining the imaging findings with the clinical scenario is very helpful in reaching a differential diagnosis during clinical practice. We will discuss the spectrum of ovarian neoplasms in the pediatric population and describe their clinical, pathologic, and imaging characteristics. A few unique entities related to ovarian tumors, such as growing teratoma syndrome, anti-N-methyl-D-aspartate receptor encephalitis, and hereditary ovarian tumor syndromes, are also discussed. In addition, we will review several entities that may mimic ovarian neoplasms as well as their distinct imaging features.

Signet ring cell carcinoma arising from sacrococcygeal teratoma: a case report and review of the literature

We report here a rare case of adult sacrococcygeal teratoma (SCT) that was pathologically diagnosed as signet ring cell carcinoma (SRCC). A 26-year-old man complained of lower abdominal distension and discomfort and difficulty in urinating, and he was admitted to our hospital. Pelvic magnetic resonance imaging showed multiple oval, solid-cystic masses around the anterior sacrococcygeal region that measured approximately 96 × 114 × 89 mm. Magnetic resonance imaging also showed irregular cysts around the posterior sacrococcygeal region that measured approximately 34 × 72 × 60 mm. The preliminary diagnosis was cystic SCT. The patient then underwent surgery, during which we incised the cysts. A large amount of viscous, jelly-like liquid was present in the anterior sacrococcygeal mass. Furthermore, a large amount of light yellow, porridge-like secretion was present in the posterior sacrococcygeal mass. A pathological examination and immunohistochemistry confirmed teratoma, specifically SRCC.

Intracranial Germ Cell Tumor in the Molecular Era

Intracranial germ cell tumors (iGCTs) are a heterogeneous group of tumors with peculiar characteristics clearly distinguished from other brain tumors of neuroepithelial origin. Diverse histology, similarity to gonadal GCT, predilection to one sex, and geographic difference in incidence all present enigmas and fascinating challenges. The treatment of iGCT has advanced for germinoma to date; thus, clinical attention has shifted from survival to long-term quality of life. However, for non-germinomatous GCT, current protocols provide only modest improvement and more innovative therapies are needed. Recently, next-generation sequencing studies have revealed the genomic landscape of iGCT. Novel mutations in the KIT-RAS-MAPK and AKT-MTOR pathways were identified. More importantly, methylation profiling revealed a new method to assess the pathogenesis of iGCT. Molecular research will unleash new knowledge on the origin of iGCT and solve the many mysteries that have lingered on this peculiar neoplasm for a long time.