Primary intracranial germ cell tumor. Pathologic study of 51 patients

Clinicopathological spectrum of central nervous system germ cell tumors: A single-institution retrospective study

CONTEXT

Central nervous system germ cell tumors (CNSGCTs) though rare is the second most common extragonadal site for GCTs.

AIMS

To determine the clinicopathological features of CNSGCTs diagnosed at our center.

SETTINGS AND DESIGN

A retrospective study of all histologically diagnosed CNSGCTs, during 2006-2019.

MATERIALS AND METHODS

The patients' data were retrieved from the hospital information systems and analyzed.

STATISTICAL ANALYSIS

Data on categorical variables were analyzed as percentages, and data on continuous variables calculated as mean. Chi-square test or Fisher's exact test was used to study association between variables.

RESULTS

Of the total 34 cases with CNSGCT, age ranged from 1 to 27 years, majority in the second decade (19/34; 56%). Male: female (M: F) ratio was 1.6:1. Single site involvement was seen in 27 cases (27/34; 79%), whereas seven (7/34; 21%) showed bi/multifocal involvement. Among the unifocal cases, common sites involved were suprasellar (12/27; 44.4%), closely followed by the pineal (10/27; 37%). All multifocal tumors affected suprasellar compartment, being bifocal with pineal in four cases. A male gender predilection was noted among pineal region (9/10;90%) and multifocal tumors (5/7;71%). Germinoma was the commonest subtype (21/34; 61.8%) with male gender predilection (17/21; 81%) (M: F =4.3:1), with female predilection seen among mixed GCTs (MGCTs) (8/10; 80%) (M: F =1:4) and suprasellar location (M: F =1:2). Serum tumor markers (25 cases) and CSF markers (7 cases) were concordant with histology in all, except two cases.

CONCLUSION

Though histology and immunohistochemistry were diagnostic, correlation between serum and/or CSF marker was essential to rule out GCT component(s) that may be missed on biopsy due to sampling error.

Primary midbrain germinomas: Report of a rare case with an updated review of the literature

Intracranial germinomas are most commonly extra-axial germ cell tumors that are predominantly found in the pineal and suprasellar regions. Primary intra-axial midbrain germinomas are extremely rare, with only eight reported cases. Here we present a 30-year-old man who presented with severe neurological deficits, with an MRI that showed a heterogeneously enhancing mass with ill-defined margins in the midbrain, and with surrounding vasogenic edema extending to the thalamus. The presumptive preoperative differential diagnosis included glial tumors and lymphoma. The patient underwent a right paramedian suboccipital craniotomy and biopsy obtained through the supracerebellar infratentorial transcollicular approach. The histopathological diagnosis was reported as pure germinoma. After patient discharge, he received chemotherapy with carboplatin and etoposide, followed by radiotherapy. Follow-up MRI at up to 26 months showed no contrast-enhancing lesions but a mild T2 FLAIR hyperintensity adjacent to the resection cavity. Differential diagnosis of midbrain lesions can be challenging and should include glial tumors, primary central nervous system lymphoma, germ cell tumors, and metastasis. Accurate diagnosis requires adequate tissue sampling. In this report, we present a very rare case of a primary intra-axial germinoma of the midbrain which is biopsied via a transcollicular approach. This report is also unique as it provides the first surgical video of an open biopsy and the microscopic appearance of an intra-axial primary midbrain germinoma via a transcollicular approach.

Benign and Malignant Tumors of the Pineal Region

Pineal region tumors fall into five broad categories: benign pineal region tumors, glial tumors, papillary tumors, pineal parenchymal tumors, and germ cell tumors. Genetic and transcriptional studies have identified key chromosomal alterations in germinomas (RUNDC3A, ASAH1, LPL) and in pineocytomas/pineoblastomas (DROSHA/DICER1, RB1). Pineal region tumors generally present with symptoms of hydrocephalus including nausea, vomiting, papilledema, and the classical Parinaud's triad of upgaze paralysis, convergence-retraction nystagmus, and light-near pupillary dissociation. Workup requires neuroimaging and tissue diagnosis via biopsy. In germinoma cases, diagnosis may be made based on serum or CSF studies for alpha-fetoprotein or beta-HCG making the preferred treatment radiosurgery, thereby preventing the need for unnecessary surgeries. Treatment generally involves three steps: CSF diversion in cases of hydrocephalus, biopsy through endoscopic or stereotactic methods, and open surgical resection. Multiple surgical approaches are possible for approach to the pineal region. The original approach to the pineal region was the interhemispheric transcallosal first described by Dandy. The most common approach is the supracerebellar infratentorial approach as it utilizes a natural anatomic corridor for access to the pineal region. The paramedian or lateral supracerebellar infratentorial approach is another improvement that uses a similar anatomic corridor but allows for preservation of midline bridging veins; this minimizes the chance for brainstem or cerebellar venous infarction. Determination of the optimal approach relies on tumor characteristics, namely location of deep venous structures to the tumor along with the lateral eccentricity of the tumor. The immediate post-operative period is important as hemorrhage or swelling can cause obstructive hydrocephalus and lead to rapid deterioration. Adjuvant therapy, whether chemotherapy or radiation, is based on tumor pathology. Improvements within pineal surgery will require improved technology for access to the pineal region along with targeted therapies that can effectively treat and prevent recurrence of malignant pineal region tumors.

Brain and Spinal Tumors Originating from the Germ Line Cells

Primary central nervous system germ cell tumors (CNS GCTs) are part of the GCTs in children and adults. This tumor entity presents with geographic variation, age, and sex predilection. There are two age peaks of incidence distribution at the first few months of life and in adolescence. CNS GCTs are heterogeneous in histopathological subtypes, locations, and tumor marker (AFP, β-hCG) secretions. In the WHO CNS tumor classification, GCTS are classified as germinoma and nongerminomatous GCT (NGGCT) with different subtypes (including teratoma). Excluding mature teratoma, the remaining NGGCTs are malignant (NGMGCT). In teratoma, growing teratoma syndrome and teratoma with somatic-type malignancy should be highlighted. The common intracranial locations are pineal region, neurohypophysis (NH), bifocal pineal-NH, basal ganglia, and cerebral ventricle. Above 50% of intracranial GCTs (IGCTs) present obstructive hydrocephalus. Spinal tumors are rare. Age, locations, hydrocephalus, and serum/CSF titer of β-hCG correlate with clinical manifestations. Delayed diagnosis is common in tumors arising in neurohypophysis, bifocal, and basal ganglia resulting in the increasing of physical dysfunction and hormonal deficits. Staging work-up includes CSF cytology for tumor cells and contrast-enhanced MRI of brain and spine for macroscopic metastasis before treatment commences. The therapeutic approach of CNS GCTs integrates locations, histopathology, staging, tumor marker level, and therapeutic classification. Treatment strategies include surgical biopsy/excision, chemotherapy, radiotherapy (single or combination). Secreting tumors with consistent imaging may not require histopathological diagnosis. Primary germinomas are highly radiosensitive and the therapeutic aim is to maintain high survival rate using optimal radiotherapy regimen with/without chemotherapy combination. Primary NGNGCTs are less radiosensitive. The therapeutic aim is to increase survival utilizing more intensive chemotherapy and radiotherapy. The negative prognostic factors are residue disease at the end of treatment and serum or CSF AFP level >1000 ng/mL at diagnosis. In refractory or recurrent NMGGCTs, besides high-dose chemotherapy, new therapy is necessary. Molecular profiling and analysis help for translational research. Survivors of pediatric brain tumors frequently experience cancer-related cognitive dysfunction, physical disability, pituitary hormone deficiency, and other CNS complications after cranial radiotherapy. Continuous surveillance and assessment may lead to improvements in treatment protocols, transdisciplinary interventions, after-treatment rehabilitation, and quality of life.

Molecular Pathology and Targeted Therapies for Personalized Management of Central Nervous System Germinoma

Intracranial germinomas are rare tumours, usually affecting male paediatric patients. They frequently develop in the pineal and suprasellar regions, causing endocrinological disturbances, visual deficits, and increased intracranial pressure. The diagnosis is established on magnetic resonance imaging (MRI), serum and cerebrospinal fluid (CSF) markers, and tumour stereotactic biopsy. Imaging techniques, such as susceptibility-weighted imaging (SWI), T2* (T2-star) gradient echo (GRE) or arterial spin labelling based perfusion-weighted MRI (ASL-PWI) facilitate the diagnosis. Germinomas are highly radiosensitive tumours, with survival rates >90% in the context of chemoradiotherapy. However, patients with resistant disease have limited therapeutic options and poor survival. The aim of this review is to highlight the genetic, epigenetic, and immunologic features, which could provide the basis for targeted therapy. Intracranial germinomas present genetic and epigenetic alterations (chromosomal aberrations, KIT, MAPK and PI3K pathways mutations, DNA hypomethylation, miRNA dysregulation) that may represent targets for therapy. Tyrosine kinase and mTOR inhibitors warrant further investigation in these cases. Immune markers, PD-1 (programmed cell death protein 1) and PD-L1 (programmed death-ligand 1), are expressed in germinomas, representing potential targets for immune checkpoint inhibitors. Resistant cases should benefit from a personalized management: genetic and immunological testing and enrolment in trials evaluating targeted therapies in intracranial germinomas.

Neuropathology of Pituitary Adenomas and Sellar Lesions

The pituitary gland is the site of numerous neoplastic and inflammatory processes. The overwhelmingly most frequent tumors arise from cells of the anterior lobe, the pituitary neuroendocrine tumors (PitNETs). Immunohistochemistry assay staining for pituitary hormones is the core tool for classifying PitNETs, resulting in the diagnosis of somatotroph PitNETs, lactotroph PitNETs, and so on. For cases showing no hormonal expression, the updated WHO classification system now considers the assessment of several transcription factors: PIT-1 (pituitary-specific POU-class homeodomain transcription factor); T-PIT (T-box family member TBX19); and SF-1 (steroidogenic factor regulating gonadotroph cell differentiation) before rendering a diagnosis of null cell adenoma. Other tumors and disease processes of this site often mimic PitNETs radiographically and sometimes even clinically (ie, compression of the optic chiasm). These potpourri of processes include germ cell neoplasms (especially germinomas), tumors that originate from Rathke's pouch (craniopharyngiomas, Rathke's cleft cyst), tumors that originate from the posterior lobe of the pituitary (pituicytoma, spindle cell oncocytoma, granular cell tumor), and tumors that originate from the meninges (especially meningiomas). In addition to neoplasms, several described inflammatory and related conditions exist that need to be distinguished from PitNETs. These include lymphocytic hypophysitis and Langerhans cell histiocytosis, a neoplastic disorder of histiocytes. In this review, we aim to briefly describe the main pituitary and sellar lesions, with emphasis on the most common tumors, the PitNETs.

Rare sphenoid ridge intracranial mature teratoma in an adult female

Intracranially located teratomas usually involve midline brain structures. However, they rarely occur in adults. A 26-year-old woman presented with a growing intracranial mass lesion in the left sphenoid ridge without neurological deficits. Magnetic resonance imaging revealed homogenous hyperintensities without contrast enhancement. The patient underwent gross total excision of the soft, yellowish sphenoid ridge tumor with no cystic component. The surgery was uneventful, with no intraoperative complications. Histological analysis revealed a mature teratoma. She attended regular outpatient neuroradiology follow-up appointments. The present case is an unusual example of a mature teratoma with regard to location, neuroimaging appearance, macroscopic intraoperative findings, histological tumor subtype, and patient age and sex.

Imaging diagnosis of basal ganglia germ cell tumors: subtype features subtype imaging features of GCTs

OBJECTIVES

To evaluate the subtype imaging features of basal ganglia germ cell tumors (GCTs).

METHODS

Clinical and imaging data of 33 basal ganglia GCTs were retrospectively analyzed, including 17 germinomas and 16 mixed germ cell tumors (MGCTs).

RESULTS

The cyst/mass ratio of germinomas (0.53 ± 0.32) was higher than that of MGCTs (0.28 ± 0.19, p = 0.030). CT density of the solid part of germinomas (41.47 ± 5.22 Hu) was significantly higher than that of MGCTs (33.64 ± 3.75 Hu, p < 0.001), while apparent diffusion coefficients (ADC, ×^10-3 mm²/s) value of the solid part was significantly lower in geminomas (0.86 ± 0.27 ×^10-3 mm²/s) than in MGCTs (1.42 ± 0.39 ×^10-3 mm²/s, p < 0.001). MGCTs were more common with intratumoral hemorrhage (68.75% vs 11.76%, p = 0.01), T1 hyperintense foci (68.75% vs 5.88%, p < 0.001) and calcification (64.29% vs 20.00%, p = 0.025) than germinomas. There was no significant difference in internal capsule involvement between the two subtypes (p = 0.303), but Wallerian degeneration was more common in germinomas than in MGCTs (70.59% vs 25.00%, p = 0.015).

CONCLUSION

The subtypes of GCT have different imaging features. Tumoral cystic-solidity, heterogeneity, ADC value, CT density, and Wallerian degeneration are helpful to differentiate germinomas and MGCTs in basal ganglia.

ADVANCES IN KNOWLEDGE

The subtypes of GCT have different histological characteristics, leading to various imaging findings. The imaging features of GCT subtypes in basal ganglia may aid clinical diagnosis and treatment.

Detecting non-germinomatous germ cell tumor component by arterial spin labeling perfusion-weighted MR imaging in central nervous system germ cell tumor

PURPOSE

Differentiating between germinoma and non-germinomatous germ cell tumor (NGGCT) is important because sensitivity to chemotherapy and/or radiotherapy is quite different between these two subgroups. In this study, we evaluated whether the arterial spin labeling (ASL) based perfusion-weighted imaging (PWI) could provide additional information for the differential diagnosis between germinoma and NGGCT.

METHOD

Between 2011 and 2018, 20 patients with central nervous system (CNS) germ cell tumor (GCT) who underwent preoperative MR imaging including ASL-PWI were enrolled in this study. Relative tumor blood flow (rTBF) was evaluated on ASL-PWI by manually placing regions of interest at gadolinium enhanced part of the tumors and normal subcortical white matter. Presence of intratumoral T1 hyperintense foci and apparent diffusion coefficient (ADC) were also evaluated. The final diagnosis was made by the combination of tumor markers and the histological diagnosis.

RESULTS

Among 20 patients of CNS-GCT, 11 were diagnosed as germinoma and 9 were diagnosed as NGGCT. In the germinoma subgroup, the rTBF ranged from 0.90 to 1.71 (mean 1.21, median 1.09), while it ranged from 1.14 to 5.75 (mean 3.91, median 3.31) in NGGCT subgroup. The receiver operating characteristic (ROC) curve showed that calculating rTBF is useful for differentiating between germinoma and NGGCT (area under the curve (AUC) 0.929, P = 0.0012) compared to intratumoral T1 hyperintense foci (AUC 0.788, P = 0.0304) and ADC (AUC 0.919, P = 0.0016).

CONCLUSIONS

High rTBF obtained by ASL-PWI implied the presence of NGGCT component. This information might help in deciding the chemotherapy/radiotherapy intensity.

Induction Chemotherapy Reduces Radiation Therapy Dose and Volume in the Treatment of Intracranial Germinoma: Results of the SMC-G13 Trial

PURPOSE

We performed a prospective single-arm trial (NCT02782754) to explore the feasibility of reducing radiation therapy (RT) dose when induction chemotherapy is combined in the treatment of intracranial germinoma with beta-human chorionic gonadotropin levels <200 mIU/mL.

METHODS AND MATERIALS

All patients aged 3 to 35 years from November 2012 to June 2018 were eligible for this study. Four cycles of induction chemotherapy were given before RT. Carboplatin/etoposide and cyclophosphamide/etoposide regimens were used in alternation every 3 weeks. A dose of 18 Gy of craniospinal RT for metastatic tumors, whole brain RT for basal ganglia tumors, or otherwise whole ventricular RT followed by 12.6 Gy of boost RT to the primary tumor bed was administered after induction chemotherapy. The primary endpoint of this study was progression-free survival.

RESULTS

A total of 41 consecutive patients were enrolled (location: suprasellar in 12, pineal in 12, both suprasellar and pineal in 11, and basal ganglia in 6 patients). Eleven patients had leptomeningeal seeding. Toxicity during chemotherapy was mild, except for bone marrow suppression. Tumor status after induction chemotherapy was complete response in 33 patients and partial response in 8. All but 2 patients completed the scheduled treatment. All patients but 1 remained event free during a median follow-up of 3.4 (range, 0.3-7.0) years from diagnosis. The 1 patient experienced relapse and died of tumor bleeding. Late effects were not significant except for neuroendocrine dysfunction already present at diagnosis. Vertical growth and cognitive function were not significantly disturbed by treatment.

CONCLUSIONS

This study showed the feasibility of reducing RT dose/volume with induction chemotherapy in pathologically pure germinoma with elevated beta-human chorionic gonadotropin levels up to 200 mIU/mL.

A primary third ventricle mixed germ cell tumor with leptomeningeal dissemination of immature teratoma component

A 17-year-old male patient presented to the clinic with a headache, nausea, and vomiting. Magnetic resonance imaging demonstrated a fat-containing and -enhancing heterogeneous tumor in the third ventricle, and fat droplets within the ventricles and the subarachnoid space. Obstructive hydrocephalus was also present. Emergency subtotal removal of the mass was performed via interhemispheric transcallosal approach. The histopathological diagnosis was a mixed germ cell tumor that was composed of embryonal carcinoma, yolk-sac tumor, germinoma, and immature teratoma containing a large amount of mature elements. The patient was referred for postoperative chemoradiotherapy. A mixed germ cell tumor is a rare type of nongerminomatous germ cell tumor that is made up of at least two different types of germ cell tumors. These may include germinoma, choriocarcinoma, embryonal carcinoma, yolk sac tumor, mature teratoma, immature teratoma, or teratoma with malignant degeneration. As far as we know, this is the first reported case of a primary third ventricle mixed germ cell tumor with leptomeningeal dissemination of the immature teratoma component that contains grossly visible mature elements at admission.

De Novo Pineal Region Germinoma in the Seventh Decade of Life: A Case Report

Germ cell tumors typically occur in children and adolescents. We here report a rare case of de novo pineal region germinoma in the seventh decade of life. A 62-year-old man presented with double vision. Computerized tomography and magnetic resonance imaging (MRI) identified a heterogeneously enhanced tumor with calcification in the pineal region with ventricular dilatation due to aqueduct stenosis. The tumor had not been observed at all on MRI obtained 2 years previously. The patient underwent endoscopic biopsy and third ventriculostomy for the obstructive hydrocephalus. The tumor was histopathologically diagnosed as a pure germinoma. The patient underwent radiomonotherapy, resulting in his complete remission, which was confirmed by a series of follow-up MRI studies and hematological examinations. Intracranial germinoma should be considered in the differential diagnosis of pineal region tumors regardless of age, even though the tumor was undetectable on the previous neuroimaging.

MRI features of pediatric intracranial germ cell tumor subtypes

Intracranial germ cell tumors differ in histology and location, and require different clinical management strategies. We characterized the imaging features that may aid pre-operative differentiation of intracranial germinomas and non-germinomatous germ cell tumors (NGGCTs). This retrospective study analyzed 85 patients with intracranial germ cell tumors and adequate preoperative or pretreatment MRIs between 2000 and 2013 at our institution. Pretreatment MRI characteristics, apparent diffusion coefficient (ADC) values, tumor histopathology, and patient outcomes were compared. NGGCTs occurred in the pineal region and cerebral hemispheres more often than germinomas; all bifocal lesions were germinomas. NGGCTs (36.6 ± 17.0 mm) were significantly larger than germinomas (25.7 ± 11.6 mm; P = 0.002). The presence of pure solid tumor (45.5 vs. 20.0%, P = 0.033) and an infiltrative margin (20.0 vs. 3.3%, P = 0.035) were significantly more common in germinomas than NGGCTs. The presence of intratumoral T1 hyperintense foci (66.7 vs. 10.9%, P < 0.001) and moderate/marked enhancement (86.7 vs. 50.9%, P < 0.001) were significantly more common in NGGCTs than in germinomas. Mean ADC_mean values (×10^-3 mm²/s) were significantly lower in germinomas (1.113 ± 0.415) than in NGGCTs (2.011 ± 0.694, P = 0.001). Combined a lack of T1 hyperintense foci and an ADC_mean threshold value (1.143 × 10^-3 mm²/s) had the highest specificity (91.3%) and positive predictive value (92.3%), while the combination of lack of a T1 hyperintensense foci, no/mild enhancement, and an ADC_mean threshold value had 100% sensitivity and 100% negative-predictive value for discriminating germinomas from NGGCTs. Pre-operative conventional MRI characteristics and diffusion-weighted MRI help clinicians to assess patients with intracranial germ cell tumors. Tumor size, location, T1 hyperintense foci, intratumoral cystic components, tumor margin and enhancing patterns demonstrate contrast between germinomas and NGGCTs. Serum tumor markers and adjunctive combination with T1 hyperintensity and/or enhancing pattern with ADC offer potential in preoperative differentiating intracranial germinomas and NGGCTs.

Teratomas of the cranial vault: a systematic analysis of clinical outcomes stratified by histopathological subtypes

BACKGROUND

Teratomas of the cranial vault are divided into histopathological subtypes and grouped by prognoses: mature (good prognosis), mixed/malignant and immature teratomas (intermediate prognosis). This schema also includes non-teratomatous tumors. The authors of this study sought to elucidate histologically dependent predictors of survival and further clarify the classification system of intracranial teratomas.

METHODS

We performed a systematic analysis of the published literature to identify studies describing patients with intracranial teratomas diagnosed with magnetic resonance imaging (MRI) and presenting definite information on histologies, therapies, and outcomes at a minimum follow-up of 2 years. Disease-free (DFS) and overall survival (OS) were evaluated.

RESULTS

A total of 18 articles comprised of 134 patients were included. On univariate analysis, male sex and gross-total resection (GTR) were associated with high mean DFS (p = 0.0362 and p < 0.0001, respectively). On multivariate analysis, mature teratomas located in the pineal, and those having undergone subtotal resection (STR) demonstrated high mean OS (p = 0.0023 and p = 0.0044, respectively). Mature and mixed/malignant suprasellar teratomas had equally higher mean OS versus immature suprasellar teratomas (p < 0.0001). Mature and immature teratomas treated with adjuvant therapy had significantly higher mean OS compared to those managed with surgery alone (p = 0.0421 and p = 0.0423, respectively). Males with immature teratomas had the highest mean OS (p < 0.0001). Immature teratomas managed with surgery alone had higher mean DFS, but lower mean OS, compared to those treated with adjuvant therapy (p = 0.0176 and p = 0.0423, respectively).

CONCLUSIONS

Our data highlight the divergent nature of the different histopathological subtypes of teratomas, and suggest that survival outcomes are multifactorial. Specifically, male sex, pineal, suprasellar, GTR, and STR were dependent predictors of OS, while histopathology was an independent predictor of OS.

Pineal germ cell tumors: Two cases with review of histopathologies and biomarkers

Pineal germ cell tumors (GCTs) are primarily seen in pediatric and Asian populations. These tumors are divided into germinomatous and non-germinomatous GCTs (NGGCTs). GCTs are thought to arise by misplacement of totipotent stem cells en route to gonads during embryogenesis. Intracranial GCTs display an affinity to develop along the pineal-suprasellar axis and have variable manifestations dependent upon the location of the tumor. Management and outcomes are driven by histopathologies. In this study, we highlight two cases of pineal GCTs and present a review of the literature with an emphasis on histopathologies and biomarkers.

Germinoma Mimicking Tumefactive Demyelinating Disease in Pediatric Patients

Cases of intracranial germinoma with granulomatous reaction are rare, so a pathological diagnosis of this disease is difficult. In this report, we describe the case of a 13-year-old boy with a bilateral thalamic germinoma which initially mimicked tumefactive demyelinating disease with inflammation, based on the clinical symptoms, imaging results and histology of a biopsy specimen obtained endoscopically. Upon examination of the cerebrospinal fluid, oligoclonal bands were detected. Although his symptoms and radiological findings improved following steroid pulse treatment, they worsened dramatically almost 1 year after the first surgery and even after an additional steroid pulse treatment. Prompted by the clinical course, a second biopsy was performed, and a pathological examination of the specimen showed a two-cell pattern. The diagnosis was changed to intracranial germinoma. After chemotherapeutic treatment with etoposide and cisplatin, the patient's symptoms and radiological findings dramatically improved. We conclude that it is very challenging to distinguish germinomas with a granulomatous reaction due to other inflammatory diseases, especially when only small specimens can be obtained. Stereotactic or endoscopic biopsies should be performed using samples from several different points even if the lesions are associated with eloquent brain regions.

Imaging characteristics of primary intracranial teratoma

BACKGROUND

Primary intracranial teratomas are rare intracranial neoplasms, and are subdivided into mature, immature, and those with malignant transformation. To date, only a few studies of teratoma imaging have been reported.

PURPOSE

To describe and characterize the magnetic resonance imaging (MRI) findings in a series of 18 patients (16 men/boys and 2 women/girls; mean age, 14.5 years) with pathologically proven teratomas.

MATERIAL AND METHODS

Findings from medical records and imaging examinations in 18 patients with pathologically confirmed intracranial teratomas from 2001 to 2011 were retrospectively reviewed at our two institutions. Two radiologists evaluated the lesion location, shape, size, number, edge, homogeneous or heterogeneous appearance, attenuation, signal intensity, and degree of enhancement.

RESULTS

All tumors were located within the pineal (n = 13), parasellar (n = 2), or suprasellar (n = 3) regions. The lesions appeared of mixed intensity on MRI, reflecting the histologic heterogeneity, including fibrosis, fatty tissue, calcification, cysts, and keratinocytes. In mature teratomas (n = 9), seven of nine tumors showed non-enhanced multilocularity or heterogeneous enhancement of the cyst wall on contrast-enhanced T1-weighted (T1W) images. Two of nine tumors showed moderate, heterogeneous enhancement in the solid portion of the lesion; whereas in immature (n = 7) or malignant transformation (n = 2) teratomas, heterogeneous, ring-like, intratumoral patchy enhancement was noted on T1W images with contrast.

CONCLUSION

Primary intracranial teratomas are usually localized in the pineal and the suprasellar regions, and often present an ovoid or lobulated mass with or without multilocularity on MRI. Marked enhancement of the solid portion or the thick wall of the tumor was the key feature for distinguishing mature teratoma and malignant teratoma.

[Intracranial germinoma masquerading as a granulomatous inflammation, diagnostic failure after brain biopsy]

We report the case of a 33-year-old man with diplopia, sleepiness, and paresthesia of the left upper limb that were slowly progressive. On admission, he presented with restriction in the vertical movement of the eyes and abduction of the right eye, and horizontal and convergence nystagmus. Slight weakness of the left upper limb, bilateral Babinski sign, and truncal ataxia were also noted. Cerebral magnetic resonance imaging was performed, and gadolinium-enhanced T1-weighted imaging revealed a mass lesion that involved the diencephalon and the corpus callosum, which was invariably enhanced. Specimens obtained using a brain biopsy showed epithelioid granuloma with the presence of foreign body giant cells and lymphocytic infiltration. Prednisolone was administrated because we suspected neurosarcoidosis, but the clinical symptoms worsened with the enlargement of the lesion. A re-evaluation of the biopsy specimens using immunohistochemistry revealed tumor cells of germinoma that were scattered among the lymphocytes and positive for periodic acid-Schiff staining, placental alkaline phosphatase, and c-kit. A combination of chemotherapy and radiation resulted in clinical improvement and marked reduction of the mass lesion in size. We concluded that the possibility of germinoma should be considered in case granulomatous inflammation is observed in brain biopsy specimens.

Recent advances in understanding the etiology and pathogenesis of pediatric germ cell tumors

Pediatric germ cell tumors (GCTs) are rare neoplasms arising predominantly in the gonads and sacrococcygeal, mediastinal, and intracranial localizations. In this article, we review current knowledge of pathogenesis of pediatric GCTs, which differs from adult/adolescent GCTs. One distinctive feature is the absence of a progenitor stage, such as carcinoma in situ or gonadoblastoma, which are seen in adult/adolescent GCTs, except spermatocytic seminoma. The primordial germ cell (PGC) is the suggested origin of all GCTs, with variations in histology reflecting differentiation stage. Expression of pluripotency transcription factors OCT-3/4, NANOG, and AP-2γ in germinomas/seminomas/dysgerminomas is consistent with retaining a germ cell phenotype. Teratomas, in contrast, develop through a pathway of aberrant somatic differentiation of immature germ cells, and the yolk sac tumors and choriocarcinomas result from abnormal extraembryonic differentiation. In pediatric GCTs, origin is suggested at an earlier developmental stage because of predisposing genetic factors, although responsible genes remain largely unknown. Some extragonadal GCTs have been linked to overexpression of the KIT/KITLG system, allowing for survival of aberrantly migrated ectopic PGCs. Infant gonadal/sacrococcygeal GCTs may be caused by apoptosis-related pathways, consistent with an association with polymorphisms in BAK1. Although recent advances have identified candidate pathways, further effort is needed to answer central questions of pathogenesis of these fascinating tumors.

Histopathology of pineal germ cell tumors

Germ cell tumors (GCTs) classically occur in gonads. However, they are the most frequent neoplasms in the pineal region. The pineal location of GCTs may be caused by the neoplastic transformation of a primordial germ cell that has mismigrated. The World Health Organization (WHO) recognizes 5 histological types of intracranial GCTs: germinoma and non-germinomatous tumors including embryonal carcinoma, yolk sac tumor, choriocarcinoma and mature or immature teratoma. Germinomas and teratomas are frequently encountered as pure tumors whereas the other types are mostly part of mixed GCTs. In this situation, the neuropathologist has to be able to identify each component of a GCT. When diagnosis is difficult, use of recent immunohistochemical markers such as OCT(octamer-binding transcription factor)3/4, Glypican 3, SALL(sal-like protein)4 may be required. OCT3/4 is helpful in the diagnosis of germinomas, Glypican 3 in the diagnosis of yolk sac tumors and SALL4 in the diagnosis of the germ cell nature of an intracranial tumor. When the germ cell nature of a pineal tumor is doubtful, the finding of an isochromosome 12p suggests the diagnosis of GCT. The final pathological report should always be confronted with the clinical data, especially the serum or cerebrospinal fluid levels of β-human chorionic gonadotropin (HCG) and alpha-fetoprotein.

Endocrine dysfunction in Taiwanese children with human chorionic gonadotropin-secreting germ cell tumors

BACKGROUND/PURPOSE

Human chorionic gonadotropin (HCG)-secreting germ cell tumors (GCTs) are rare childhood malignancies with unique clinical manifestations but delayed diagnosis is common. The purpose of this study is to investigate the clinical manifestations and endocrine dysfunction of Taiwanese children with HCG-secreting GCTs.

METHODS

From 1991 to 2011, 24 children (19 boys and five girls) with HCG-secreting GCTs were evaluated for their clinical findings and endocrine functions.

RESULTS

The mean age at diagnosis of the study patients was 10.8 ± 3.1 years. Of the 24 patients, 20 had central nervous system (CNS) GCTs and four had primary mediastinal GCTs (PMGCTs). The most common pathologic findings were germinomas and mixed type GCTs. The common initial symptoms and signs included polyuria, polydipsia, rapid growth, neurologic deficit,sexual precocity, and growth retardation. There was a delay in diagnosis in about 60% of patients. Diabetes insipidus and hypopituitarism were common endocrine dysfunctions in patients with CNSGCTs. Twelve boys had gonadotropin-independent puberty upon diagnosis, which were related to their high serum β-hCG levels. None of the five girls had this disorder despite their high serum β-hCG levels. Three of the four PMGCTs patients had the classic form of Klinefelter syndrome.

CONCLUSION

Taiwanese children with HCG-secreting GCTs often have clinical manifestations related to endocrine dysfunction. High index of suspicion is important to avoid delayed diagnosis in these children.

Neuropsychological functions and quality of life in survived patients with intracranial germ cell tumors after treatment

BACKGROUND

The notable survival chances of intracranial germ cell tumors (icGCTs) lead to a rising concern over long-term neurocognitive outcome. Yet, prior evidence related to this issue fails to provide a comprehensive examination of the effects of tumor location and radiotherapy. We attempt to explore their impacts on the neuropsychological functions and life quality in children with icGCT after multimodality treatments.

METHODS

A retrospective review of 56 patients diagnosed with icGCTs at age <20 and treated at the Taipei Veterans General Hospital was provided. Intelligence, memory, visual organization, attention, and executive function were assessed by neurocognitive tests; adaptation to life, emotional and behavioral changes, interpersonal relationships, and impact on the family were evaluated by parent-report instruments. Effects of tumor locations (germinomas and nongerminomatous malignant germ cell tumors in the pineal, suprasellar, and basal ganglia) and irradiation on these measurements were examined.

RESULTS

Patients with tumors in the basal ganglia region had lower full-scale IQs than those with tumors in the pineal or suprasellar regions. Subscores of intelligence scale and short-term retention of verbal and visual stimuli showed evident group differences, as did the quality of life and adaptive skills, particularly in psychosocial domains. Patients treated with whole-ventricular irradiation had better outcomes. Extensive irradiation field and high irradiation dosage influenced intellectual functions, concept crystallization, executive function, and memory.

CONCLUSIONS

Tumor location and irradiation field/dosage appear to be the crucial factors related to certain neuropsychological, emotional, and behavioral dysfunctions that in turn alter the quality of life in children with icGCTs who survive after treatment.

Congenital intracranial immature teratoma of the lateral ventricle: a case report and review of the literature

OBJECTIVE

Congenital intracranial tumors are very rare and only account for 0.5-1.5% of all childhood brain tumors. The most common type of these tumors present at birth is teratomas, which represent 0.5% of all intracranial tumors. Most teratomas are midline tumors located predominantly in the sellar and pineal regions. In this study, we report a neonatal intracranial immature teratoma at the lateral ventricle because of its rare location.

CASE REPORT

A 3-day-old female neonate presented with a history of irritability, vomiting, and recurrent generalized clonic seizures since birth. A head computed tomographic scan and magnetic resonance imaging disclosed a large tumor filling the right lateral ventricle and extending into the ipsilateral posterior fossa. With right parieto-occipital craniotomy, large grayish-white lobulated vascular mass was encountered and total removal of tumor was performed. Histological examination revealed the diagnosis of immature teratoma.

CONCLUSION

The prognosis of congenital intracranial immature teratoma is usually poor because the lesions are extensive when they are identified. Prenatal ultrasonography is necessary for the prenatal diagnosis. Fetal magnetic resonance imaging should be made for the evaluation of intracranial tumor. If the tumor is detected before the 24 week of gestation, termination of the pregnancy should be considered.

Paediatric germ cell tumours of the central nervous system: Results and experience from a tertiary-referral paediatric institution in Australia

A retrospective analysis was conducted on consecutive patients with intracranial germ cell tumours diagnosed and treated from 1 January 1997 to 31 December 2007 to assess and determine demographic factors and treatment outcomes of children with these tumours treated in a major paediatric referral hospital in Australia. In this study, intracranial germ cell tumours represented 4.8% of paediatric brain tumours seen. Of the 21 patients identified, 15 (71.4%) were diagnosed with pure germinoma and six (28.6%) with non-germinomatous germ cell tumours (NGGCT) or mixed tumours. One patient received chemotherapy alone, two patients were treated with radiation alone and the remaining 18 received a combination of chemotherapy and radiotherapy. A total of 33 neurosurgical operations were performed with 15 biopsies via open, endoscopic or transphenoidal means; nine open resections; and nine procedures for hydrocephalus comprising seven third ventriculostomies and two ventriculoperitoneal shunts. For patients with pure germinomas, the 5-year disease-free rate (DFS) was 93.3%, and overall survival (OS) rate was 100% compared to NGGCT or mixed tumours (DFS 50%; OS 50%) (DFS p=0.019, OS p=0.004). The data presented show that pure germinomas carry a favourable prognosis. The data also support that treatment with induction chemotherapy followed by dose-attenuated radiotherapy is an effective alternative with results comparable to historical controls treated with craniospinal irradiation. Although chemoradiotherapy has become the mainstay of treatment in intracranial germ cell tumours, surgery remains integral to the management of this condition. Surgery remains important in establishing the histological diagnosis, as well as in the treatment of hydrocephalus. Furthermore, debulking procedures may be advocated in NGGCT as they are often resistant to chemotherapy.

Risk factors for osteoporosis in long-term survivors of intracranial germ cell tumors

SUMMARY

We measured bone mineral densities in 28 intracranial germ cell tumor long-term survivors. There was the high prevalence of osteoporosis and osteopenia, 25.0% and 42.9%, respectively, and three additional risk factors, male sex, a low lean mass, and adult growth hormone replacement, were identified.

INTRODUCTION

Intracranial germ cell tumor long-term survivors (iGCTLS) have many risk factors for osteoporosis, including irradiation from cancer therapy and multiple hormone deficiencies. However, no study of bone mineral density (BMD) has been conducted in iGCTLS because these tumors are rare. The aims of this study were to evaluate the prevalence of osteoporosis and to identify risk factors associated with reduced bone mass in iGCTLS.

METHODS

We evaluated BMD and body composition of 28 iGCTLS (10.9 ± 5.2 years after cancer treatment; 13 males) using dual-energy X-ray absorptiometry. To determine risk factors, we analyzed the medical history, including the nature of the tumor, treatment modality, endocrine status, hormone replacement therapy, lifestyle, and biochemical parameters.

RESULTS

Twenty-five percent of iGCTLS were diagnosed with osteoporosis and 42.9% with osteopenia. Most males (92.3%) had low BMD. Lean mass (LM) was positively correlated with BMD in all regions of interest, and the starting age of adult growth hormone (GH) replacement was negatively correlated with the BMD Z-score at the femur neck. In logistic regression analysis, male sex and low LM were related to low BMD.

CONCLUSIONS

The iGCTLS had a high prevalence of low BMD. We found that male sex, low LM, and delayed start of adult GH replacement were risk factors for osteoporosis. Therefore, the BMD of all iGCTLS should be evaluated, and if it is low, proper management should be started early.

Treatment strategies for initially disseminated intracranial germinomas: experiences at a single institute

PURPOSE

Initially disseminated intracranial germinomas (IDIGs) can be observed in pre-adult and adolescent brain tumor patients. However, the disease prognosis is undetermined, and the method of optimal treatment remains controversial.

METHODS

From January 1990 to January 2011, data on 91 intracranial germinoma patients (≤20 years old) were gathered from the Pediatric Brain Tumor database at Taipei Veterans General Hospital. A total of seven patients with a median age of 17.0 years had IDIGs (lesion sites >2), including IDIGs in the ventricular system or the spinal column. Craniospinal irradiation (CSI) plus a primary or metastatic boost was the mainstay strategy for radiotherapy. Six out of a total of seven patients (85.7%) also received systemic chemotherapy (CHT) after radiotherapy. Survivals rates between IDIGs and patients without dissemination were estimated using the Kaplan-Meier method.

RESULTS

The median follow-up time for all seven patients was 67.5 months (range, 10.3-142.3 months). None of the IDIG patients experienced a recurrence or mortality after the completion of treatment. The 5- and 10-year disease-free survival (DFS) between IDIG and non-dissemination patients were 100%, 100%, 93.0% and 78.6%, respectively (p = 0.339). The 5- and 10-year overall survival (OS) between IDIGs and non-dissemination cases were 100%, 100%, 93.7% and 89.4%, respectively (p = 0.473).

CONCLUSIONS

IDIG patients did not show reduced survival compared to non-dissemination patients if optimal radiotherapy and chemotherapy were used together.

A multimodal approach including craniospinal irradiation improves the treatment outcome of high-risk intracranial nongerminomatous germ cell tumors

PURPOSE

To evaluate whether a multimodal approach including craniospinal irradiation (CSI) improves treatment outcome in nongerminomatous germ cell tumor (NGGCT) patients.

METHODS AND MATERIALS

We reviewed the records of 32 patients with NGGCTs. Fourteen patients belonged to the intermediate prognosis group (immature teratoma, teratoma with malignant transformation, and mixed tumors mainly composed of germinoma or teratoma), and 18 patients belonged to the poor prognosis group (other highly malignant tumors). Patients with pure germinoma or mature teratoma were excluded from this study. Nineteen patients were treated with a combination of surgery, chemotherapy, and radiotherapy (RT); 9 patients received chemotherapy plus RT; 3 patients received surgery plus RT; and 1 patient received RT alone. Twenty-seven patients received CSI with a median of 36 Gy (range, 20-41 Gy) plus focal boost of 18-30.6 Gy, and 5 patients received whole-brain RT (WBRT) (20-36 Gy) or focal RT (50.4-54 Gy). The rate of total and subtotal resection was 71.9%. The median follow-up for surviving patients was 121 months.

RESULTS

Treatment failed in 7 patients. Three of the 5 patients who received focal RT or WBRT had local failure. Four cerebrospinal fluid (CSF) failures occurred after CSI. No failure occurred in the intermediate prognosis group. Ten-year recurrence-free survival (RFS) and overall survival (OS) for all patients were 77.6% and 74.6%, respectively. Ten-year RFS for the intermediate and poor prognosis groups were 100% and 61.1%, respectively (p = 0.012). OS for the two groups were 85.1% and 66.7%, respectively (p = 0.215). Tumor histology and CSI were significant prognostic factors for RFS, and CSI was significantly associated with OS.

CONCLUSIONS

A multimodal approach was effective for treating NGGCTs. CSI should be considered for patients with poor prognostic histology.

Primary CNS teratocarcinoma

Primary central nervous system (CNS) teratomas are rare tumors that consist of all three germ cell layers. We describe a young man with a primary malignant CNS teratocarcinoma presenting as leptomeningeal carcinomatosis. Diagnosis of primary CNS teratocarcinomas is challenging; relentless pursuit of the diagnosis must follow even if early ancillary studies are inconclusive.

Change in treatment strategy for intracranial germinoma: long-term follow-up experience at a single institute

BACKGROUND

Previous intracranial germinoma (IG) studies have investigated the effect of different radiotherapy (RT) volumes and the necessity for adjunctive chemotherapy, but there is currently no consensus on the best treatment for this tumor.

METHODS

From January 1989 to December 2009, 80 IG patients (≤20 years old) were treated with various RT regimens. Of them, 14 patients had craniospinal irradiation (CSI) + primary boost (PB); 8 patients had whole-brain irradiation (WBI) + PB; 31 patients had whole ventricular irradiation (WVI) + PB; and 27 patients had focal RT only. Twenty-nine patients (36.2%) also received systemic chemotherapy (CHT). Survival was estimated by the Kaplan-Meier method and variables affecting survival were analyzed by the Cox proportional hazard model.

RESULTS

Eleven patients (13.8%) developed local recurrence or dissemination after treatment, and 10 of these patients were in the focal RT group. The 5-year relapse-free survival (RFS) for the CSI, WBI, WVI, and focal RT patients were 100%, 85.7%, 100%, and 84.6%, respectively (P = .001). The 5-year overall survival (OS) for CSI, WBI, WVI, and focal RT patients was 100%, 83.3%, 100%, and 87.9%, respectively (P = .125). Focal irradiation (P = .02) and initial use of CHT (P = .021) were negatively associated with RFS.

CONCLUSIONS

Focal RT plus CHT were associated with inferior control of IG and a higher incidence of CHT-related toxicities. Adjustment of the radiation volume to the whole ventricular system without CHT is sufficient for treatment of nondisseminated IGs, even with lower primary RT doses (<36 Gy).

HESRG: a novel biomarker for intracranial germinoma and embryonal carcinoma

The novel stem cell-related gene, HESRG, was first identified by our group, and its expression pattern in human tumors remains unknown. In this study, we used RT-PCR to systematically investigate the expression of HESRG in various types of intracranial tumors and found that HESRG was expressed only in germinoma and embryonal carcinoma, but hardly at all in other types of brain tumors. Real-time PCR results further confirmed this expression pattern. Subsequently, we tested 134 intracranial non-germ cell tumors and 64 intracranial germ cell tumors by immunohistochemistry. Our results showed that HESRG was expressed strongly and diffusively in the nuclei of tumor cells in intracranial germinoma and embryonal carcinoma as well as in human embryonic stem cells. No positive staining signal was observed in any other type of intracranial tumors. In germinomas, 25 of 31 showed intensive (3+) expression, four cases showed moderate (2+) immunostaining and the remaining 2 cases showed weak (1+) immunostaining. In embryonal carcinoma, 6 of 9 showed intensive (3+) immunostaining and 3 of 9 showed moderate (2+) immunostaining. These results suggest that HESRG is a novel, sensitive and specific biomarker for intracranial germinoma and embryonal carcinoma.

Pituitary choriocarcinoma in an adolescent male: tumor-derived CG and GH delay diagnosis

BACKGROUND

Primary intracranial germ cell tumors usually present in the first two decades of life, often with precocious puberty. The most common location is in the pineal gland; suprasellar germ cell tumors are rare. We present an additional case of a suprasellar choriocarcinoma producing GH, and review the literature.

CASE

This French Canadian, 17 year-old male presented to the ER with a history of mild weight loss and an episode of syncope while hiking in Mexico, but with no other neurological symptoms. Puberty began at age 13 years (growth spurt: 15-16 years), and he attained an adult height within genetic target by age 16 years. Past medical history was negative except for myopia diagnosed during childhood. System review revealed increased thirst and nocturia. The mother was treated for an oligo-astrocytoma in 2007. Clinical examination showed a euthyroid, well-looking young man with 20 ml testicles. Endocrine evaluation revealed elevated testosterone, mildly elevated PRL, borderline low FT4, and decreased IGF-I, morning cortisol and urine osmolality; tumor markers were positive in serum and CSF (hCG>50 IU/L, AFP>10 ng/mL). A transphenoidal biopsy of a 4.5 cm, homogeneous, non-calcified, suprasellar mass was compatible with the diagnosis of choriocarcinoma and stained intensely for hCG and hGH, presumably the placental variant (GH-V) as previously found in vitro in choriocarcinoma cell lines. Combined chemotherapy and irradiation led to tumor regression and undetectable serum hCG to 36 months of follow-up. He is doing well with no evidence of tumor progression and is on complete hormone replacement therapy.

CONCLUSIONS

Choriocarcinomas can have a hormonal profile that delays the development of symptoms, due to hCG stimulation of both the gonadal and thyroid axes. This report corroborates previous in vitro evidence that choriocarcinoma cells are able to make GH-V. To what extent the patient's tumor-derived GH contributed to his normal growth is not known. Prognosis for this intracranial neoplasm is very reserved, although combined radiotherapy and chemotherapy has been successful in our patient now 36 months post-diagnosis.

Pleomorphic granular cell astrocytoma in the pineal gland: case report

Pleomorphic granular cell astrocytoma in the pineal region is exceedingly rare, and its clinicopathological features are distinctive. A 67-year-old woman was admitted with a staggering gait. Magnetic resonance imaging revealed a mass lesion at the pineal gland accompanied by obstructive hydrocephalus. Following surgery, pathological examinations demonstrated a pleomorphic granular cell astrocytoma. The patient has been free from recurrence for 24 months after surgery without adjuvant therapy. The specimen exhibited nuclear and cytoplasmic pleomorphism. The nuclei varied in size, shape and coarseness. Variability was also observed in the eosinophilic granular bodies, Rosenthal fibers and spindle-shaped tumor cells. GFAP, S-100 and vimentin were immunohistochemically positive. Reticulin network was absent between the tumor cells, and granular cells with ballooned cytoplasm showing positive staining for PAS. Pleomorphic granular cell astrocytoma is believed to be a form of astrocytoma originating from the pineal gland. Its clinicopathological features resemble those of pleomorphic xanthoastrocytoma. However, it can be differentiated from the latter by the absence of reticulin fibers, absence of basement membrane between adjacent cells, and presence of large numbers of mitochondria.

Pineal mixed germ cell tumor with a synchronous sellar lesion in the sixth decade

Intracranial germ cell tumors (GCTs) typically affect children and adolescents. We here report on a 59-year-old male patient presenting with diplopia, polydipsia and polyuria. On clinical examination, slight restriction of the upward gaze was seen on the left side. Computed tomography demonstrated calcifications in the pineal region and enhanced neurohypophysis. Magnetic resonance imaging displayed a heterogeneous pineal mass of 3-cm diameter, which was multicystic with an enhanced cyst wall, and also swelling of the pituitary stalk. The pineal lesion of the tumor, which included calcifications and keratinaceous components, was totally excised using an occipital transtentorial approach. Histopathological examination showed it to be a mixed GCT with germinoma and mature teratoma components. Postoperative chemoradiotherapy provided complete disappearance of the suprasellar lesion. To our knowledge, this is the first case of mixed bifocal GCT in an older adult reported in the literature, although a few cases of tumors with a single histological component have been reported. Hence, our case further underlines the possibility of the occurrence of GCTs in older adults and advocates the consideration of GCTs in the differential diagnosis of such cases for appropriate management.

The use of immunohistochemistry in the diagnosis of metastatic clear cell renal cell carcinoma: a review of PAX-8, PAX-2, hKIM-1, RCCma, and CD10

The diagnosis of metastatic clear cell renal cell carcinoma may be difficult in some cases, particularly in the small image-guided biopsies that are becoming more common. As targeted therapies for renal cell carcinoma are now standard treatment, the recognition and diagnosis of renal cell carcinoma has become even more critical. Many adjunctive immunohistochemical markers of renal epithelial lineage such as CD10 and RCCma have been proposed as aids in the diagnosis of metastatic renal cell carcinoma, but low specificities often limit their utility. More recently described markers (PAX-2, PAX-8, human kidney injury molecule-1, hepatocyte nuclear factor-1-β, and carbonic anhydrase-IX) offer the potential for greater sensitivity and specificity in this diagnostic setting; however, knowledge of their expected staining in other neoplasms and tissues is critical for appropriate use. In this review, we discuss the most widely used immunohistochemical markers of renal lineage with an emphasis on their sensitivity and specificity for metastatic clear cell renal cell carcinoma. Subsequently, we present a variety of organ-specific differential diagnostic scenarios in which metastatic clear cell renal cell carcinoma might be considered and we propose immunopanels for use in each situation.

High Alpha-Fetoprotein Persistence after Orchiectomy. On a Case of Uncommon Etiology

Background

The following report describes a case of inherited elevation of alpha-fetoprotein (AFP) in a young male suspected for testicular cancer. AFP shows very high values during fetal life. After birth the synthesis of AFP decreases dramatically, and only trace amounts are detected in the adult. From this age on, serum AFP can rise above normal in some diseases, e.g. liver disorders, and in some kind of tumors. A condition in which persistent high levels of AFP are found, named Hereditary Persistence of AFP [HPAFP), was first reported in 1983 by Ferguson-Smith, and then recorded in the literature only on eleven occasions till 2004. The occurrence of HPAFP may be underestimated. HPAFP can be easily confirmed by testing AFP levels in blood-related family members.

Methods

An elevated serum AFP (about 20 μg/mL) was found in a 27–year-old white man with an unremarkable medical history, who was concerned to have left testicular cancer. By our examination, his left testis was markedly reduced in size. β-HCG, LDH, and liver function were normal. Surgical inguinal exploration with testis and spermatic cord excision was carried out. Postoperative repeated AFP levels remained persistently elevated, in the range from 20 to 30 μg/mL. Careful evaluation for occult cancer showed no abnormality. Histology showed necrotic tissue and could not make a reliable diagnosis. A literature search was done using PubMed by key word “alpha-fetoprotein” and “elevation”. Thinking of a hereditary trait, we decided to screen patient's blood-related family members.

Results

AFP was found to be elevated in another four out of six relatives within three generations, unrelated to any disease. This pedigree was consistent with an autosomal dominant inheritance pattern.

Conclusions

HPAFP could mislead the physician. Failure to recognize HPAFP can lead to unsuitable treatments. The existence of this clinically benign condition needs to be considered in both children and adults with unexplained and persistent elevation of AFP, e.g. those diagnosed or suspected for germ cell tumor.

Histopathology of tumors of the pineal region

Pineal region tumors are heterogeneous lesions and include mainly pineal parenchymal tumors (PPTs), papillary tumors of the pineal region (PTPRs) and germ cell tumors (GCTs). This article describes the cystic pineal gland compared with normal tissue and histopathological features of the most frequent pineal region tumors. PPTs are subdivided into pineocytoma (grade I), pineoblastoma (grade IV) and tumors with intermediate differentiation (PPTIDs; grades II-III). A grading system based on the number of mitoses and neurofilament protein expression distinguishes low- from high-grade PPTID. PTPR is a new tumoral entity thought to originate from the subcommissural organ. GCTs include germinoma, embryonal carcinoma, teratoma, yolk sac tumor and choriocarcinoma and are often of mixed histologic composition. New histogenetic data for GCTs are presented.

Suprasellar/pineal bifocal germ cell tumors

PURPOSE

Intracranial germ cell tumors (GCT) arise from embryonal rests of germinal cells. The aim of this report is to analyze a small group of GCT located simultaneously in the suprasellar and pineal regions without seeding either between both tumors or to other places. We named this group as suprasellar/pineal bifocal germ cell tumors (SPBT).

METHODS

A retrospective review of a series of 25 GCT showed a) 16 cases of unifocal non-disseminated pineal or sellar GCT, b) one case of unifocal disseminated pineal GCT, c) three cases with suprasellar and pineal double tumors with dissemination, and d) five cases with SPBT. The analysis is focused on the latter group.

RESULTS

The series includes four pure germinomas and one germinal non-germinoma. MRI and endoscopic exploration were necessary to define SPBT. Endocrine, ocular, and increased intracranial pressure syndromes were identified and related to the size of the tumors. Chemotherapy and radiotherapy were performed in all SPBT. Radical or partial resection of SPBT offered no benefits over biopsy. Prognosis for bifocal groups was similar to unifocal tumors of the same histological type. Complete remission without recurrence and mortality were achieved in all cases.

CONCLUSIONS

SPBT seem to be an entity defined by a) one tumor in the suprasellar and another in the pineal region, b) GCT with predominance of PG, but not exclusively, and c) MRI and endoscopy without any dissemination. The presence of two tumors does not indicate dissemination; SPBT were non-disseminated but focal tumors, and spinal radiotherapy was not necessary.

Gonadotrophin-independent precocious puberty in an eight-year-old boy due to ectopic human chorionic gonadotrophin from the central nervous system

We present the case of an eight-year-old boy with advanced isosexual precocity associated with an elevated serum total-beta human chorionic gonadotrophin (HCG) and markedly elevated serum total testosterone. Radiological investigation discovered a lesion in the left thalamus and no peripheral tumour. Serum:cerebrospinal fluid (CSF) HCG ratio was approximately 1:1, consistent with a central nervous system source of HCG, with thalamic germinoma strongly suspected. Consent was not obtained for biopsy of the lesion. The patient underwent multiagent chemotherapy with return of serum HCG to normal. We discuss mechanisms of HCG-mediated sexual precocity in both boys and girls and the importance of CSF HCG.

Diagnostic utility of SALL4 in extragonadal yolk sac tumors: an immunohistochemical study of 59 cases with comparison to placental-like alkaline phosphatase, alpha-fetoprotein, and glypican-3

Extragonadal yolk sac tumors (YSTs; primary and metastatic) are rare but are malignant germ cell tumors. Pathologic diagnosis of extragonadal YSTs can be challenging without immunohistochemical markers but markers used for diagnosing these tumors such as placental-like alkaline phosphatase (PLAP), alpha-fetoprotein (AFP), and glypican-3 lack adequate sensitivity and/or specificity. In earlier studies with gonadal germ cell tumors, SALL4 has been identified as a novel diagnostic marker for YSTs and other types of primitive germ cell tumors. Here, we investigated the diagnostic utility of SALL4 in 59 extragonadal YSTs (27 primary sacrococcygeal, 15 primary nonsacrococcygeal, and 17 metastatic) by immunohistochemical staining. We also compared SALL4 with PLAP, AFP, and glypican-3. In addition, we performed immunostains for pancytokeratin, epithelial membrane antigen, and OCT4 in these tumors. Our results showed that all 59 YSTs showed strong pancytokeratin staining (70% tumor cells in 1 case, >90% tumor cells in 58) and 10 (17%) of them also showed focal epithelial membrane antigen staining (<3% tumor cells). All 59 YSTs were negative for OCT4. Strong SALL4 staining was seen in all 59 YSTs (in more than 90% tumor cells in 54 and 70% to 85% tumor cells in 5 YSTs). Only 39 of 59 (66%) YSTs showed positive PLAP staining and the staining was often focal (in less than 30% tumor cells) (28 of 39 cases). Positive AFP staining was seen in the vast majority of YSTs (56 of 59 or 95%); however, 32 (54%) YSTs showed staining in less than 30% tumor cells. Although all 59 YSTs showed positive glypican-3 staining, 18 (30%) showed staining in less than 30% tumor cells, and additional 10 (17%) showed staining in between 30% and 60% tumor cells. In these 59 YSTs, the mean percentage of tumor cells stained with PLAP was 14% (range: 0% to 90%), with AFP 35% (range 0% to 95%), and with glypican-3 57% (range: 1% to 100%), whereas the mean percentage of tumor cells stained for SALL4 was 94% (range: 70% to 100%) (P<0.001). Our results indicate that SALL4 is a novel sensitive (100% sensitivity) diagnostic marker for extragonadal YSTs. SALL4 is a more sensitive marker than PLAP, AFP, or glypican-3 for extragonadal YSTs.

Diagnostic utility of SALL4 in primary germ cell tumors of the central nervous system: a study of 77 cases

Primary germ cell tumors of the central nervous system (CNS) sometimes pose diagnostic difficulty. In this study we analyzed the diagnostic utility of a novel marker, SALL4, in 77 such tumors (59 pure and 18 mixed) consisting of the following tumors/tumor components: 49 germinomas, 7 embryonal carcinomas, 27 yolk sac tumors, 3 choriocarcinomas, and 14 teratomas. We also stained SALL4 in 99 primary non-germ cell tumors to test SALL4 specificity. We compared SALL4 with OCT4 in all germ cell tumors and compared SALL4 with alpha-fetoprotein and glypican-3 in all yolk sac tumors. The staining was semiquantitatively scored as 0 (no staining), 1+ (<or=30%), 2+(31-60%), 3+ (61-90%), and 4+ (>90%). Strong SALL4 staining was observed in all 49 germinomas (4+ in 48, 3+ in 1), 7 embryonal carcinomas (all 4+), and 27 yolk sac tumors (1+ in 1, 2+ in 2, 3+ in 7, 4+ in 17). SALL4 staining, 1+ weak to focally strong, was observed in 2 of 3 choriocarcinomas (in mononucleated trophoblasts) and in 9 of 14 teratomas (in primitive neuroepithelium and teratomatous glands). All germinomas and embryonal carcinomas showed strong OCT4 staining (4+ in all except 1 germinoma with 3+), whereas other germ cell tumors were negative. Out of 27 yolk sac tumors, 26 showed positive alpha-fetoprotein staining (1+ in 9, 2+ in 7, 3+ in 5, and 4+ in 5). All yolk sac tumors showed positive glypican-3 staining (1+ in 6, 2+ in 6, 3+ in 7, and 4+ in 8). The mean percentage of yolk sac tumor cells stained was 84% with SALL4, 45% with alpha-fetoprotein, and 63% with glypican-3 (P<0.01). No non-germ cell tumors showed SALL4 staining. Our results indicate that SALL4 is a novel sensitive diagnostic marker for primary germ cell tumors of the CNS with high specificity. SALL4 is a more sensitive marker than alpha-fetoprotein and glypican-3 for yolk sac tumors.

Central nervous system germ cell tumors: classification, clinical features, and treatment with a historical overview

Central nervous system germ cell tumors are neoplasms that affect children and young adults. They are subclassified into germinoma and nongerminomatous germ cell tumors. The latter include teratoma (mature teratoma, immature teratoma, teratoma with malignant transformation), choriocarcinoma, embryonal carcinoma, yolk sac tumors, and mixtures of these entities. Germinoma with syncytiotrophoblastic giant cells is a variant of germinoma. Germinomas respond well to radiation therapy, but late sequelae due to irradiation have been reported. The results of radiation treatment alone for nongerminomatous germ cell tumor are not satisfactory. Combination radiochemotherapy has been applied, and this yields a good outcome with less toxicity for germinomas and better survival of nongerminomatous germ cell tumors. This article also discusses other issues, including the controversy regarding spinal irradiation and the treatment of recurrent disease.

Germ cell tumors of the brainstem: report on two cases with pulmonary complications and a review of the literature

Intracranial germ cell tumors most commonly present in the pineal and suprasellar regions. Rare cases of brainstem germ cell tumors have been described. Here, we present two cases with brainstem germ cell tumors and review the current literature. The two patients did well, in terms of disease control, but have significant morbidity related to respiratory issues. One patient remains ventilator dependent and the second died from respiratory arrest.