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Primary yolk sac tumor of the orbit is a rare entity. Orbital involvement is usually seen in young children and proptosis is the commonest presentation. Aggressive orbital involvement and presentation as a fungating mass is rarely seen. We report a case of primary orbital yolk sac tumor with an aggressive presentation that responded well to systemic chemotherapy.

Background: Endodermal sinus tumor (EST) is a malignant tumor originating from the ovary or testis. In most case, ultrasound examination shows ovarian mass. But there is a special kind of extra-gonadal endodermal sinus tumor, which occur in organs other than gonads with insidious onset. Here we reported a case of endodermal sinus tumor, which originated from the sacral ligament presenting as an acute lower abdominal pain., Case Presentation: A 14-year-old girl was admitted to the hospital because of acute lower abdominal pain. The ultrasound showed a mass with 72 mm × 64 mm × 50 mm in Douglas, and there was no abnormality in bilateral ovaries and fallopian tubes. Laparoscopic exploration showed a large amount of blood clots in the pelvic cavity. After removal of the blood, we found rotten fish-like tissue in the left sacral ligament, rapid pathology suggested endodermal sinus tumor. After the operation, we retrospectively examined the value of alpha-fetoprotein (AFP), which was found to be elevated, and post-operative paraffin pathology confirmed the diagnosis. After four cycles of BEP chemotherapy, exploratory laparotomy was performed to remove the visible lesion, but postoperative pathology showed no abnormality. At the one-year follow-up, the patient remained recurrence-free., Conclusion: Extra-gonadal germ cell tumors are rarely reported. When young teenagers complain of acute lower abdominal pain with elevated AFP, but there was no lesion in bilateral ovaries and fallopian tubes, we must think about the possibility of endodermal sinus tumors. Accurate diagnosis facilitates complete resection of lesions and improves patient's outcomes., (© 2023. The Author(s).)

The role of surgery for metastases to the vertebra from yolk sac tumours has not been established. The main treatment for disseminated disease is chemotherapy. We present a man in his 30s with a left orchiectomy for a testicular mixed germ cell tumour with a prominent yolk sac component who, 12 months later, developed an asymptomatic metastasis to the L2 vertebra unresponsive to chemotherapy and radiotherapy. The patient underwent resection of the L2 vertebral body, leaving a small residual tumour anterior to the vertebra attached to the great vessels. Pathology confirmed the diagnosis of a metastatic testicular yolk sac tumour in the vertebra. The postoperative MRI 6 months later demonstrated significant expansion of the tumour at the soft tissues anterior to the expandable titanium cage encasing the great vessels and extending to the paraspinal areas. Additional salvage surgery was not recommended because of the advanced stage of the tumour., Competing Interests: Competing interests: None declared., (© BMJ Publishing Group Limited 2022. No commercial re-use. See rights and permissions. Published by BMJ.)

Abstract: Pineal yolk sac tumors (YSTs) are a rare type of extragonadal YST. They make up a small fraction of all intracranial germ cell tumors and an even small fraction of pineal masses overall. This study reported a case of pineal YST with α-fetoprotein production revealed by 18F-FDG and 68Ga-FAPI PET/MRI. In the PET images, 68Ga-FAPI showed a far better tumor-to-background ratio than 18F-FDG in the pineal YST because there is little 68Ga-FAPI uptake in the brain. This case indicates that 68Ga-FAPI PET/MRI may be a useful tool for evaluating intracranial YST and other types of tumors in central nervous system., Competing Interests: Conflicts of interest and sources of funding: none declared., (Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.)

BACKGROUND Existing literature has detailed occurrences of retroperitoneal yolk sac tumors (YSTs) as the result of metastasis from a primary gonadal site. However, primary retroperitoneal YSTs are extremely rare, thus remaining a challenge to diagnose and treat. We present a complex case of a large primary retroperitoneal YST in a man treated with neoadjuvant chemotherapy followed by surgical resection. CASE REPORT A 31-year-old man presented with a chief symptom of severe lower abdominal pain. Diagnostic imaging revealed a large, rapidly progressing neoplasm in the retroperitoneal region, initially thought to be a sarcoma. However, the pathological results from further biopsies found the mass to be a retroperitoneal YST, which was tethered to a large portion of the small bowel. A testicular ultrasound was used to confirm that the mass was a primary tumor with no origins in the gonads. The tumor progressed to involve several fistulas connected to the small intestine and anterior abdominal wall. The patient was treated with 3 cycles of bleomycin, etoposide, and cisplatin, followed by surgical excision of the residual mass. The patient retained normal gastrointestinal functions, and subsequent imaging revealed no evidence of recurrence 2.5 years following resection. CONCLUSIONS Owing to the rarity of extragonadal primary YSTs, diagnostic and treatment standards have not yet been sufficiently explored. Our case demonstrates that a combination of chemotherapy and surgical resection should be considered for select patients with primary YST in the retroperitoneal region.

Purpose: Yolk sac tumor (YST) is a rare malignant germ cell tumor and typically occurs in gonads. It is extremely rare in the brain, especially in the fourth ventricle., Methods: This study reported the case of a 3-year-old boy with intermittent vomiting for 11 days and then intermittent twitch for 5 h., Results: Brain computed tomography showed a slightly higher density mass in the fourth ventricle. Brain magnetic resonance imaging showed an irregular lobulated expansive mass in the fourth ventricle, appearing with the low intensity on T1-weighted images, and uneven hyperintensity on T2-weighted images. The enhanced scan showed inhomogeneous and strong enhancement, with multiple small cyst-like areas of no enhancement. Tortuous tumor vessel also can be seen. The pathological results after surgical resection showed an YST in the fourth ventricle., Conclusion: When a mass is observed in the fourth ventricle in children, with uneven signal with hemorrhage and cystic change, inhomogeneous and strong enhancement, and facilitated diffusion on diffusion-weighted imaging, YST should be considered. The increase of α-fetoprotein value can help differential diagnosis.

Yolk sac tumor (YST) is a rare and highly malignant germ cell tumor that is extremely rare in the nasal region. Herein, we present a case of biopsy-proven nasal YST admixed with transitional cell carcinoma in a 58-year-old woman. Complementary F-FDG PET/CT revealed the only FDG-avid mass in the right nasal cavity. This case indicates that YST could occur in the nasal region primarily, and F-FDG PET/CT is a useful tool to distinguish between primary and metastatic lesions.

Objective: To describe the clinical and sonographic characteristics of malignant ovarian yolk sac tumors (YSTs)., Methods: In this retrospective multicenter study, we included 21 patients with a histological diagnosis of ovarian YST and available transvaginal ultrasound images and/or videoclips and/or a detailed ultrasound report. Ten patients identified from the International Ovarian Tumor Analysis (IOTA) studies had undergone a standardized preoperative ultrasound examination, by an experienced ultrasound examiner, between 1999 and 2016. A further 11 patients were identified through medical files, for whom ultrasound images were retrieved from local image workstations and picture archiving and communication systems. All tumors were described using IOTA terminology. The collected ultrasound images and videoclips were used by two observers for additional characterization of the tumors., Results: All cases were pure YSTs, except for one that was a mixed tumor (80% YST and 20% embryonal carcinoma). Median age at diagnosis was 25 (interquartile range (IQR), 19.5-30.5) years. Seventy-six percent (16/21) of women had an International Federation of Gynecology and Obstetrics (FIGO) Stage I-II tumor at diagnosis. Fifty-eight percent (11/19) of women felt pain during the ultrasound examination and one presented with ovarian torsion. Median serum α-fetoprotein (S-AFP) level was 4755 (IQR, 1071-25 303) µg/L and median serum CA 125 level was 126 (IQR, 35-227) kU/L. On ultrasound assessment, 95% (20/21) of tumors were unilateral. The median maximum tumor diameter was 157 (IQR, 107-181) mm and the largest solid component was 110 (IQR, 66-159) mm. Tumors were classified as either multilocular-solid (10/21; 48%) or solid (11/21; 52%). Papillary projections were found in 10% (2/21) of cases. Most (20/21; 95%) tumors were well vascularized (color score, 3-4) and none had acoustic shadowing. Malignancy was suspected in all cases, except in the patient with ovarian torsion, who presented a tumor with a color score of 1, which was classified as probably benign. Image and videoclip quality was considered as adequate in 18/21 cases. On review of the images and videoclips, we found that all tumors contained both solid components and cystic spaces, and that 89% (16/18) had irregular, still fine-textured and slightly hyperechoic solid tissue, giving them a characteristic appearance., Conclusion: Malignant ovarian YSTs are often detected at an early stage, in young women usually in the second or third decade of life, presenting with pain and markedly elevated S-AFP. On ultrasound, malignant ovarian YSTs are mostly unilateral, large and multilocular-solid or solid, with fine-textured slightly hyperechoic solid tissue and rich vascularization. © 2020 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of the International Society of Ultrasound in Obstetrics and Gynecology.., (© 2020 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of the International Society of Ultrasound in Obstetrics and Gynecology.)

Yolk sac tumor is a rare and highly malignant germ cell tumor. We report a case of yolk sac tumor primarily in the pancreas in a 32-year-old man. He presented with pancreatitis at presentation with significantly increased serum alpha-fetoprotein (AFP). F-FDG PET/CT revealed diffuse enlargement of the pancreas in the neck, body, and tail portion with homogeneously increased FDG uptake, similar to the change of pancreatitis. The lesion progressively developed to a huge pancreatic mass in the follow-up images, and endoscopic ultrasonography-guided aspiration biopsy of the pancreatic mass confirmed the diagnosis of yolk sac tumor.

Purpose: The aim of this study is to analyze retrospectively the computed tomography and magnetic resonance imaging (MRI) features of pediatric vaginal endodermal sinus tumor (EST) and rhabdomyosarcoma (RMS) in a case series., Methods: Seven children with vaginal EST and 2 children with vaginal RMS underwent MRI and/or computed tomography examination before the biopsy and treatment. Images were evaluated by 2 observers for the following features: (a) tumor extent; (b) margin; (c) tumor shape; (d) tumor size; (e) architecture (solid, cystic, or mixed cystic-solid); (f) hemorrhage, necrosis, and calcification; (g) magnetic resonance T2 signal intensity; (h) pattern of the enhancement; and (i) signal intensity on diffusion-weighted imaging and apparent diffusion coefficient (ADC) value., Results: All of the 7 ESTs showed as a round-shaped solid mass with a location limited to the vagina without vulva and bladder invasion, whereas RMSs have an irregular grape-like appearance filling the whole vagina with vulva and bladder invasion. The invasion to the cervix was not observed in EST or RMS. Both EST and RMS were heterogeneously hyperintense on T2-weighted magnetic resonance images and enhanced remarkably and heterogeneously. Heterogeneous high signal on diffusion-weighted imaging were observed in vaginal EST and RMS. The ESTs showed a lower ADC value (mean, 1.04×10 mm/s), while RMSs showed a relatively high ADC value (mean, 1.51 × 10 mm/s)., Conclusions: Computed tomography and MRI may be useful tools in diagnosing the vaginal RMS and EST.

Objectives: To understand that yolk sac tumors (YSTs) of the head and neck (H&N) are exceedingly rare and typically carry a poor prognosis. To acknowledge the possibility of increased incidence in patients with Aicardi Syndrome and the ramifications this has on early diagnosis and treatment in this population., Methods: To date, four germ cells tumors of the H&N have been reported in patients with Aicardi Syndrome. This report presents the second known case of a H&N YST in a patient with Aicardi syndrome. In both cases, the patient was initially misdiagnosed given unconvincing radiologic evidence. However, tissue diagnosis and elevated alpha-fetoprotein (AFP) levels were suggestive of a YST., Results: In contrast to the poor prognosis previously described, both patients with Aicardi syndrome had an excellent chemotherapeutic response exhibited by normalization of AFP levels and imaging., Conclusions: Rare germ cell tumors of the H&N, such as YSTs, have now been documented in several patients with Aicardi syndrome, indicating a possible association given the rarity of these tumors in the population. YSTs should be considered in the differential diagnosis of H&N masses in these patients, with emphasis on early tissue diagnosis and treatment.

Extragonadal germ cell tumors are germ cell tumors with no evidence of a primary tumor within the gonads, most often located in the mediastinum or retroperitoneum. We present an extragonadal yolk sac tumor that presented as an adrenal carcinoma and required left adrenalectomy, nephrectomy, and significant IVC thrombectomy. This case, to our knowledge, is the first documented case of extragonadal yolk sac tumor originating from the adrenal gland.

Background: Mixed germ cell tumors (MGCTs) usually occur in children. In the present report, we discuss an extremely rare case of adult-onset MGCT composed mainly of yolk sac tumor (YST) around the pineal gland., Case Description: A 54-year-old Japanese man presented with disturbance of consciousness, Parinaud's syndrome, and gait disturbance. Magnetic resonance imaging revealed a pineal mass lesion, and subtotal resection of the tumor was achieved. The histologic diagnosis was MGCT, consisting mainly of YST. Although he underwent 5 courses of chemotherapy and craniospinal irradiation after surgery, tumor dissemination could not be controlled, and he died 10 months postoperatively., Conclusion: The present case highlights the need for clinicians to include YST in the differential diagnosis of acute progressive lesions around the pineal region, even in adult patients., (Copyright © 2019 Elsevier Inc. All rights reserved.)

OBJECTIVE. The objective of our study was to evaluate the clinical utility of FDG PET/CT in staging and restaging pediatric patients with yolk sac tumor (YST). MATERIALS AND METHODS. We retrospectively reviewed the data from 31 pediatric patients with pathologically confirmed YST who underwent 34 PET/CT studies for the purpose of staging or restaging. The PET/CT studies were read by two nuclear medicine doctors in consensus. Histopathology combined with clinical and imaging follow-up was taken as the reference standard. The results of PET/CT were also compared with conventional imaging and α-fetoprotein (AFP) levels when available. RESULTS. Of the total 34 studies, six were performed for initial staging and the other 28 for posttherapy evaluation. FDG PET/CT was true-positive in all six staging studies, detected only a few more metastatic foci than conventional imaging, and changed the therapeutic regimen in none of the six patients. Nevertheless, PET/CT showed high accuracy in the restaging group, with a sensitivity of 100% and specificity of 85.7%. The treatment regimen was changed in 46.4% of the patients in the restaging group according to the PET/CT study. In addition, PET/CT had higher accuracy than AFP levels in YST restaging. Overall, the per-study performance of PET/CT was a sensitivity of 100%, specificity of 85.7%, positive predictive value of 90.9%, and negative predictive value of 100%. CONCLUSION. FDG PET/CT was only slightly superior to conventional imaging in staging YST in pediatric patients. However, PET/CT of posttherapy patients with YST showed high diagnostic accuracy and had a great impact on therapeutic management.

Yolk sac tumour (YST), the most common germ cell tumour (GCT) in infants and children, accounts for 80% of GCTs in this age group. 1 It is observed in only 2.4% of adult patients in their pure form since up to 42% of mixed GCTs have some component of the yolk sac. 2 We present a 46-year-old cryptorchid man who presented with complaints of abdominal lump, pain and altered bowel habits since 1 month. CT scan of the abdomen revealed a mass arising from the pelvic cavity with feeders predominantly from the left gonadal vessel. Mass was excised via exploratory laparotomy and sent for histological examination. Microscopic examination was suggestive of pure YST. Immunohistochemistry stained positive for cytokeratin, placental-like alkaline phosphatase, Glypican 3 and alpha fetoprotein. The patient succumbed prior to commencing chemotherapy. Pure YSTs of post-pubertal origins are extremely rare and are more aggressive than their prepubertal counterparts., Competing Interests: Competing interests: None declared., (© BMJ Publishing Group Limited 2019. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Primary gastric yolk tumours are extremely rare. We report a 52-year-old male who presented to the Sultan Qaboos University Hospital, Muscat, Oman, in 2017 after having undergone a gastrectomy abroad due to a suspected poorly-differentiated adenocarcinoma. The patient subsequently returned to Oman to receive chemotherapy. However, while undergoing chemotherapy, an abdominal computed tomography scan revealed a lobulated mesenteric mass. Microscopic examination of the resected lesion confirmed a diagnosis of a yolk sac tumour. The mass was diffusely positive for α-fetoprotein (AFP) and a gastric carcinoma stain was negative. Gastrectomy slides from the patient's previous surgery were examined retrospectively. The morphology was typical for a yolk sac tumour and was negative for epithelial markers. An AFP stain showed diffuse immunoreactivity. Thus, the patient was deemed to have had a primary gastric yolk sac tumour which had later metastasised to the mesocolon. Germ cell tumour protocols were initiated and the patient responded well to treatment.

Yolk sac tumor (YST) is a rare malignancy typically occurring in children. However, bilateral testicular YSTs are a quite rare situation, which can occur metachronously or synchronously with same histologic type, as well as different histology. We present a case of synchronous YST of the left testis and mature teratoma of the right in a 7-month-old infant treated with testis-sparing surgery at right testis and high radical orchiectomy at left. By follow-up of 28th month, no atrophy, or residual tumor in right testis and no recurrence or evidence of disease in left scrotum was found., (Copyright © 2018 Elsevier Inc. All rights reserved.)

BACKGROUND Cardiac involvement by a malignant tumor is rare. However, this is a case of right heart failure due to cardiac metastasis from a yolk sac tumor. Although a few case reports of cardiac metastasis from yolk sac tumors have been published, to our knowledge this is the first instance of multiple metastases to the right ventricular of yolk sac tumor in an adult male. CASE REPORT The patient is a 46-year-old male with a history of testicular cancer that presented with dyspnea on exertion. He was found to have two large right sided intracardiac masses on echocardiography. Cardiac magnetic resonance imaging (MRI) was obtained to further investigate these masses. Right ventricular function was decreased and concern for right ventricular outflow tract (RVOT) obstruction was present. The patient was taken to the operating room (OR) for resection of the cardiac masses. Pathology revealed the masses to be yolk sac tumors. Despite urgent resection of the tumors, the patient deteriorated clinically, ultimately succumbing to heart failure. CONCLUSIONS This unique presentation of a yolk sac tumor emphasizes the need to keep a broad differential and complete a thorough workup for any cardiac mass. Early diagnosis and treatment of intra-cardiac masses is imperative due to their high rates of mortality. Albeit an uncommon etiology for heart failure, germ cell tumors can potentially metastasize to the heart and present with such a clinical picture.

Introduction: In children, malignant tumors presenting as a calvarial mass that too as initial manifestation are unusual. Also, brain metastases per se are rare in pediatric solid tumors with an incidence of just 1.5%., Case Description: We present a child with calvarial metastasis which was the presenting symptom of an otherwise asymptomatic large malignant mediastinal germ cell tumor (GCT). The lesion was dural-based involving both calvaria as well as the underlying brain parenchyma. Despite such multicompartmental location, no obvious bony destruction was seen. A 12-year-old boy presented with progressively enlarging scalp swelling and features of raised intracranial pressure. The lesion was totally excised and calvarial defect reconstructed using titanium mesh. Though the preoperative chest computed tomography suggested teratoma, the histopathology of the cranial lesion was a yolk sac tumor (YST)., Conclusion: Initial manifestation of GCT as calvarial swelling, pure YST (with no other germ cell component), and the eccentric multicompartmental (dural based) location rather than usual midline GCTs is noteworthy. The report thus highlights an atypical presentation in GCT. Although uncommon, it is worthwhile to consider metastatic GCT as a differential among calvarial lesions.

Introduction: Treatment options for patients with platinum refractory metastatic germ cell tumours (GCT) relapsing after high-dose chemotherapy and autologous stem cell transplantation are limited and survival is poor. Antibodies directed against programmed cell death protein-1 (PD-1) and programmed cell death ligand-1 (PD-L1) are currently assessed within clinical trials. We present updated data on our experience with checkpoint inhibitors as a compassionate use off-label treatment attempt for highly-pretreated patients with GCT and provide an overview of the current literature on PD-L1 expression in this rare tumour entity., Patients and Methods: We analysed all patients with platinum refractory GCT treated with checkpoint inhibitors at our institutions between 2015 and 2017. Data were retrieved retrospectively from the patient charts., Results: Seven patients were treated with nivolumab or pembrolizumab. Four patients received single-dose treatment and died shortly afterwards due to tumour progression; the remaining three patients received treatment for at least 6 months. No significant treatment toxicity was observed. Long-term tumour response was achieved in two of the three patients, both of them highly positive for PD-L1 staining., Interpretation: We consider checkpoint inhibition to be efficient in carefully selected patients with platinum refractory GCT. However, predictive markers associated with tumour response are not yet known and larger prospective clinical trials are warranted., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Tumors arising from urachus in children are exceedingly rare and sporadically reported in literature. Being a midline structure, the urachus may harbor neoplastic germ cell elements and can occasionally present as a case of acute abdomen. A 20-month-old toddler presented with spontaneous rupture of an urachal yolk sac tumor causing hemoperitoneum. He underwent resection, received platinum-based chemotherapy and presently remains well on follow-up. Despite its rarity, urachal germ cell tumors must be considered in a child with acute abdomen and tumor markers must be measured preemptively in such cases.

Background: The accurate histologic diagnosis of germ cell tumors in the pineal region is a keystone for determining the best treatment strategy and prognosis. This situation poses a challenge for the neuropathologist, considering the lack of a standarized procedure to obtain biopsy samples, which results in few and small specimens, which are not suitable for diagnosis., Case Description: We report a case in which a pineal region mixed germ cell tumor was accurately diagnosed by performing histologic mapping through a dual burr-hole endoscopic approach. The technical pitfalls and other considerations necessary for obtaining an accurate diagnosis in this tumor subgroup are specified. In addition, the histologic analysis regarding the sampling technique used is described., Conclusions: The supraorbital frontal endoscopic approach enables the surgeon to perform histologic mapping of pineal region tumors, allowing standarization of the procedure used to obtain the specimens. This approach could result in a more accurate diagnosis, especially in mixed germ cell neoplasms., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Background and Objective: Pediatric basal ganglia germ cell tumors (GCTs) represent a rare subset of tumors about which little is known. We aimed to summarize the clinical features and radiological findings of this special subgroup of GCTs., Methods: From January 2010 to January 2015, 12 pediatric patients with basal ganglia GCTs were treated in our hospital. The clinical features, radiologic findings, diagnosis, treatment, and outcome of these patients were analyzed retrospectively. Our institutional diagnostic principle and treatment strategy of this disease were discussed., Results: GCTs accounted for 25.5% of all the pediatric basal ganglia tumors treated in our hospital. There were 9 male and 3 female patients with a mean age of 11.5 ± 2.1 years. The most common symptom was progressive hemiparesis (n = 9, 75%). The radiologic findings showed that the lesions predominately located in caput of caudate nucleus (n = 9, 75.0%), followed by lenticular nucleus (n = 3, 25.0%). Hemiatrophy was commonly observed (n = 8, 66.7%). Eight patients were diagnosed as having germinomas, and 4 patients as having nongerminomatous germ cell tumors. During the follow-up period, preoperative neurologic dysfunctions improved in 7 patients and remained stable in 3. Two patients developed new onset of neurologic dysfunction after the treatment. Two patients suffered from tumor recurrence., Conclusions: GCTs are not as rare as considered in pediatric basal ganglia tumors. They bear some distinctive clinical and radiologic features, which can help with the accurate diagnosis and successful management of such tumors., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Six patients (aged 3-36 mo) with vaginal tumors (rhabdomyosarcoma and endodermal sinus tumor [EST]; n = 3 each) received intraarterial chemotherapy (IAC) and intravenous chemotherapy. Patients underwent internal iliac artery infusion with cisplatin, pirarubicin, and vindesine. Intravenous chemotherapy with vindesine, ifosfamide, and etoposide was administered after 3 weeks. Vaginal tumors disappeared in all patients after 2 or 3 cycles of alternating therapy. Two patients underwent resection of pelvic metastases. Intravenous consolidation chemotherapy was applied. Four patients were disease-free at a median follow-up of 5.8 years. One patient had pelvic recurrence treated with "salvage" therapy with IAC and surgery and was disease-free for 2.5 years., (Copyright © 2016 SIR. Published by Elsevier Inc. All rights reserved.)

Malignant mediastinal yolk sac tumor (YST), especially adult onset, is rare. Herein, we report a case of occult mediastinal YST with α-fetoprotein production revealed by F-FDG PET/CT in a young adult, in which the intense tracer uptake was demonstrated in the anterior mediastinum. This case indicates F-FDG PET/CT may be a useful tool for detecting the occult primaries of YST.

Background: Yolk sac tumor (YST) is a rare tumor. Familiarity of its radiological characteristics may permit preoperative diagnosis and improve surgical management of patients. However, a detailed description of the imaging features of YST with pathological correlation in particular is scarce., Purpose: To investigate computed tomography (CT) findings of YSTs with pathological correlation., Material and Methods: CT images of 20 patients with pathologically proven YST were retrospectively reviewed. The location, size, margin, internal architecture, and pattern and degree enhancement of the lesion were evaluated. Radiological findings were correlated with pathological results., Results: The locations of 20 tumors were distributed between the testis (n = 3), ovary (n = 6), sacrococcygeal area (n = 6), rectum (n = 1), and mediastinum (n = 4). The median age was 13 years. On CT images, all tumors were seen as oval (n = 14) or irregular (n = 6), well-defined (n = 16) or ill-defined (n = 4) masses with a mean size of 9.7 cm. The lesions were solid cystic (n = 10), entirely solid (n = 6), or predominantly cystic (n = 4). Intratumoral hemorrhage, calcification, and fatty tissue were seen in nine, three, and two tumors, respectively. Discontinuity of the tumor wall was seen in eight tumors. After contrast media administration, most tumors showed heterogeneous moderate to marked enhancement (n = 7) or heterogeneous marked enhancement (n = 9). Enlarged intratumoral vessels were seen in 17 tumors., Conclusion: YST usually appears as a large solid-cystic mass with intratumoral hemorrhage, capsular tear, marked heterogeneous enhancement, and enlarged intratumoral vessels on CT images. Intratumoral calcification and fatty tissue, although rare, may indicate a mixed YST containing teratoma component., (© The Foundation Acta Radiologica 2014.)

Ovarian yolk sac tumors (YSTs) are rare neoplasms. No radiological study has been done to compare the imaging findings between this type of tumor and other ovarian tumors. Here we analyzed the CT findings of 11 pathologically proven ovarian YSTs and compared their imaging findings with 18 other types of ovarian tumors in the same age range. Patient age, tumor size, tumor shape, ascites and metastasis of two groups did not differ significantly (P > 0.05). A mixed solid-cystic nature, intratumoral hemorrhage, marked enhancement and dilated intratumoral vessel of two groups differed significantly (P < 0.05). The area under the ROC curve of four significant CT features was 0.679, 0.707, 0.705, and 1.000, respectively. Multivariate logistic regression analysis identified two independent signs of YST: intratumoral hemorrhage and marked enhancement. Our results show that certain suggestive CT signs that may be valuable for improving the accuracy of imaging diagnosis of YST and may be helpful in distinguishing YST from other ovarian tumors.

An intrapericardial vacuolated mass compressing and displacing the heart was diagnosed by echocardiography in a foetus of 22 weeks gestation. The birth was induced for early signs of foetal distress at 29 weeks and, after two initial pericardial evacuation procedures, the tumour was resected radically 7 days after birth at a weight of 1.55 kg. Mass histology showed teratoma associated with yolk sac tumour. We comment on the overall approach adopted after foetal diagnosis and the histopathological features of the tumour, and try to draw conclusions on patient outcome data.

Malignant sacrococcygeal yolk sac tumor is a rare extra-gonadal germ cell tumor of infancy and childhood. We report the case of a 14-month-old white female infant with a rapidly growing supra-gluteal mass at first misdiagnosed as hemangioma after a clinical assessment. The lesion was then classified as extra-gonadal yolk sac tumor due to alarming ultrasound features, later confirmed at MRI and pathology. This report remarks the need of a rigorous methodology in the ultrasound exploration of the gluteal region.

Malignant germ cell tumors of the ovary are very rare and account for about 2-5% of all ovarian tumors of germ origin. Most patients are adolescent and young women, approximately two-thirds of them are under 20 years of age, occasionally in postmenopausal women. But clear cell carcinoma usually occurs in older patients (median age: 57-year old), and closely related with endometriosis. Here we report a case of a 55-year old woman with right ovarian mass that discovered by B ultrasonic. Her serum levels of human chorionic gonadotropin (hCG) and α-fetoprotein (AFP) were elevated. Pathological examination revealed the tumor to be a mixed germ cell tumor (yolk sac tumor, embryonal carcinoma and mature teratoma) with clear cell carcinoma in a background of endometriosis. Immunohistochemical staining showed SALL4 and PLAP were positive in germ cell tumor area, hCG, CD30 and OCT4 were positive in epithelial-like cells and giant synctiotrophoblastic cells, AFP, AAT, CD117 and Glyp3 were positive in yolk sac component, EMA and CK7 were positive in clear cell carcinoma, CD10 was positive in endometrial cells of endometriotic area. She was treated with surgery followed by seven courses of chemotherapy. She is well and serum levels of hCG and AFP have been decreased to normal levels.

Background: Malignant mediastinal germ cell tumors are a rare disease and represent only 1% to 4% of all mediastinal tumors. Gonadal germ cell tumors are generally the most common type and constitute 90% of germ cell tumors. The mediastinum is the second most frequently affected area ahead of other extragonadal areas, which include the retroperitoneum, the sacrococcygeal area, and the central nervous system. We report on the case of a mediastinal yolk sac tumor with a complete histological response to chemotherapy., Case Presentation: A 26-year-old Moroccan man, without a medical or surgical history, presented with a four-month history of chest distress, dyspnea, and a frequent dry cough for the previous month. A computed tomographic scan of the chest revealed a bulky mediastinal mass, which was biopsied. Histologically, the tumoral mass proved to be a yolk sac tumor. The serum level of alpha-fetoprotein of this patient was elevated to 19052 ng/ml.After 4 courses of preoperative chemotherapy, the patient underwent a surgical resection of the tumor, with a complete pathologic response.At the time of writing, the patient is alive with complete remission without any evidence of recurrence., Conclusion: Primary mediastinal Yolk sac neoplasm represent a unique entity, and as such require specialized management. The diagnosis should be made not only by morphological studies but the patient's age and the elevation of serum alpha-fetoprotein should also be considered. The utilization of cisplatin-based chemotherapy is associated with the best chance of a cure for this disease. This should be followed by surgical resection of the residual tumor in the nonseminomatous germ cell tumor.