Primitive neuroectodermal tumors in the central nervous system following cranial irradiation: a report of four cases

Radiation associated tumors following therapeutic cranial radiation

BACKGROUND

A serious, albeit rare, sequel of therapeutic ionizing radiotherapy is delayed development of a new, histologically distinct neoplasm within the radiation field.

METHODS

We identified 27 cases, from a 10-year period, of intracranial tumors arising after cranial irradiation. The original lesions for which cranial radiation was used for treatment included: tinea capitis (1), acute lymphoblastic leukemia (ALL; 5), sarcoma (1), scalp hemangioma (1), cranial nerve schwannoma (1) and primary (13) and metastatic (1) brain tumors, pituitary tumor (1), germinoma (1), pinealoma (1), and unknown histology (1). Dose of cranial irradiation ranged from 1800 to 6500 cGy, with a mean of 4596 cGy. Age at cranial irradiation ranged from 1 month to 43 years, with a mean of 13.4 years.

RESULTS

Latency between radiotherapy and diagnosis of a radiation-induced neoplasm ranged from 4 to 47 years (mean 18.8 years). Radiation-induced tumors included: meningiomas (14), sarcomas (7), malignant astrocytomas (4), and medulloblastomas (2). Data were analyzed to evaluate possible correlations between gender, age at irradiation, dose of irradiation, latency, use of chemotherapy, and radiation-induced neoplasm histology. Significant correlations existed between age at cranial irradiation and development of either a benign neoplasm (mean age 8.5 years) versus a malignant neoplasm (mean age 20.3; P = 0.012), and development of either a meningioma (mean age 7.0 years) or a sarcoma (mean age 27.4 years; P = 0.0001). There was also a significant positive correlation between latency and development of either a meningioma (mean latency 21.8 years) or a sarcoma (mean latency 7.7 years; P = 0.001). The correlation between dose of cranial irradiation and development of either a meningioma (mean dose 4128 cGy) or a sarcoma (mean dose 5631 cGy) approached significance (P = 0.059).

CONCLUSIONS

Our study is the first to show that younger patients had a longer latency period and were more likely to have lower-grade lesions (e.g. meningiomas) as a secondary neoplasm, while older patients had a shorter latency period and were more likely to have higher-grade lesions (e.g. sarcomas).

A review of secondary central nervous system tumors after treatment of a primary pediatric malignancy

Despite remarkable strides in the treatment of pediatric malignancies over the last 50 years, long-lasting sequelae and secondary malignancies continue to plague this population. This article reviews the incidence, diagnosis, and etiology of secondary central nervous system tumors in the setting of a history of primary pediatric malignancy. Particular attention is paid to central nervous system tumors presenting after treatment of leukemia and primary brain tumors, as well as the role of treatment and underlying cancer predisposition syndromes in the risk of developing these secondary tumors.

Primitive neuroectodermal tumor after radiation therapy for craniopharyngioma

The authors report a case of primitive neuroectodermal tumor induced by radiation therapy of craniopharyngioma. This African-American male patient originally presented with craniopharyngioma, for which he underwent resection and whole-brain radiation therapy. Eight years later, at the age of 20 years, he returned with a left facial droop and left hemiparesis. A right basal ganglia mass was identified and resected. Histopathological examination identified the lesion as primitive neuroectodermal tumor. Although radiation therapy has shown to be beneficial in decreasing the recurrence rate in subtotally resected craniopharyngioma, the risks of radiation treatment should be clearly communicated to the patients, their families, and neurosurgeons before starting such treatment. This report expands the spectrum of reported radiation-induced neoplasms in the CNS.

Radiotherapy-induced supratentorial primitive neuroectodermal tumour in a 17-year-old female: a case report and review of the literature

We report a case of a 17-year-old female who presented with a CNS primitive neuroectodermal tumour 12 years after cranial radiotherapy for relapsed childhood acute lymphoblastic leukaemia. In this article, we discuss the association of these rare tumours with previous craniospinal irradiation and review the pertinent literature.

Radiation-induced adult medulloblastoma: a two-case report and review of the literature

Radiation-induced medulloblastoma is an exceedingly rare phenomenon for which treatment standards have not been established. The literature suggests that these tumors are high grade with aggressive behavior. We report two cases of radiation-induced medulloblastoma which have been treated with full dose re-irradiation with curative intent. In both cases, treatment toxicity and tumor progression proved to be insurmountable obstacles. Further reports are necessary in order to fully characterize this clinical entity so that more effective therapies may be sought.

Radiation-induced glioblastoma multiforme in children treated for medulloblastoma with characteristics of both medulloblastoma and glioblastoma multiforme

Outcomes for average-risk medulloblastoma are excellent with 5-year event-free survival and overall survival>80%. Treatment failures include radiation-induced glioblastomas (RIG), which are often diagnosed solely on imaging. Recent studies suggest that RIGs differ from spontaneous glioblastoma multiforme (GBM), based on microarray gene-expression profiling. Retrospective review of children with average-risk medulloblastoma treated from 1996 to 2003 included 16 patients with 5 treatment failures. One died of disease progression, 1 died as a result of radiation necrosis, and 3 children died of pathology-confirmed GBM. Of these 3 GBMs, one was studied with electron microscopy, cytogenetics, and gene-expression microarray analysis. This tumor had focal medulloblastoma and similarity by gene-expression microarray with other RIGs. With both components in the recurrent tumor, we suggest it was in the process of transitioning from medulloblastoma to RIG, that is, "catching the tumor in the act." Some radiation-induced nervous system tumors may develop as a direct result of severe oncologic changes within the original tumor cells, with the tumor evolving into a different phenotypic tumor type. We recommend biopsy for tissue confirmation and genetic expression profile to shed light on the etiology of radiation-induced neoplasms.

Ataxia-telangiectasia: atypical presentation and toxicity of cancer treatment

BACKGROUND

The onset of progressive cerebellar ataxia in early childhood is considered a key feature of ataxia-telangiectasia (A-T), accompanied by ocular apraxia, telangiectasias, immunodeficiency, cancer susceptibility and hypersensitivity to ionizing radiation.

METHODS

We describe the clinical features and course of three Mennonite children who were diagnosed with A-T following the completion of therapy for lymphoid malignancies.

RESULTS

Prior to cancer therapy, all had non-progressive atypical neurological abnormalities, with onset by age 30 months, including dysarthria, dyskinesia, hypotonia and/or dystonia, without telangiectasias. Cerebellar ataxia was noted in only one of the children and was mild until his death at age eight years. None had severe infections. All three children were "cured" of their lymphoid malignancies, but experienced severe adverse effects from the treatments administered. The two children who received cranial irradiation developed supratentorial primitive neuroectodermal tumors of the brain, an association not previously described, with fatal outcomes.

CONCLUSIONS

The range of neurological presentations of A-T is broad. Ataxia and telangiectasias may be minimal or absent and the course seemingly non-progressive. The diagnosis of A-T should be considered in all children with neuromotor dysfunction or peripheral neuropathy, particularly those who develop lymphoid malignancies. The consequences of missing the diagnosis may be dire. Radiation therapy and radiomimetic drugs should be avoided in individuals with A-T.

Radiation-induced gliomas following radiotherapy for craniopharyngiomas: a case report and review of the literature

The aim of this study was to collect, describe and analyze the radiation-induced gliomas in craniopharyngioma patients reported in the literature up to date. Review of the relevant literature was performed. One personal illustrative case was added. Reports of 15 patients, including the presented illustrative case, were evaluated. The average age of the patients at the time of irradiation was 12.5 years. All patients underwent conventional fractionated radiotherapy with mean total radiation dose of 55Gy and an average latency period of 10.8 years. Glioma localization varied with the highest frequency of the temporal lobe involvement. All but one patient had high-grade gliomas on the histological exam. Although exceptionally rare, the radiation-induced gliomas in craniopharyngioma patients are potentially possible, long-term complications with devastating consequences in typically younger patients with long life-expectancy. The radiation-induced iatrogenic injury on one hand should provoke the research and elaboration of safer and at least, equally efficient alternative treatment modalities and on the other hand ought to prompt the investigation of the patients' risk factors predisposing the oncogenesis after irradiation.

Possible involvement of brain tumour stem cells in the emergence of a fast-growing malignant meningioma after surgical resection and radiotherapy of high-grade astrocytoma: case report and preliminary laboratory investigation

The case of a 62-year old man diagnosed with radiation-induced meningioma (RIM) after treatment for astrocytoma with an unusually short latency period of 7 months is reported. The patient first presented with a 2-month history of memory decline. Magnetic resonance imaging (MRI) showed a tumour in the left parieto-temporal lobe. Gross total resection was performed and the tumour was confirmed to be an astrocytoma. The patient received cranial radiotherapy 2 weeks later, however 7 months after radiation treatment the patient presented with headache and vomiting. MRI showed massive meningeal enhancement in the left frontal lobe, which progressively enlarged. The patient's clinical condition deteriorated and a second craniotomy was performed with complete removal of the secondary tumour, which was shown to be a malignant meningioma. Immunohistochemical staining identified CD133-positive cells in both tumours. A rare fraction of brain tumour stem cells (BTSC) was isolated from the primary astrocytoma using a serum-free culture system, suggesting that BTSC may have been involved in the rapid emergence of RIM after resection and radiation of the primary astrocytoma.

Radiation-induced brain tumours after central nervous system irradiation in childhood: a review

OBJECTS

Radiation-induced cerebral tumours constitute a significant risk for subjects undergoing radiotherapy for the management of cerebral neoplasms. Age-related cerebral vulnerability could be a specific factor in the genesis of these complications.

METHODS

The pertinent literature of both paediatric and adult series has been reviewed. Three personal cases were added.

RESULTS

One hundred forty-two paediatric second brain tumours were evaluated. Out of them, 69 were malignant gliomas, 33 meningiomas, 8 sarcomatous lesions and 13 low-grade astrocytomas. The average latency period for the appearance of the second tumour was 8 years. Among the second tumours occurring in adults, meningioma is the most common. In this subgroup, the latency period ranged between 16 and 30 years.

CONCLUSION

Paediatric radiation-induced brain tumours differ from the adult counterpart for both the histological subtypes. These figures indicate a specific vulnerability of the infantile brain demonstrated by the most frequent occurrence of highly malignant lesions.

Occurrence of a spinal anaplastic pilocytic astrocytoma and a supratentorial PNET in an adolescent

A 15-year-old girl was diagnosed with a spinal anaplastic pilocytic astrocytoma. The histologic features were similar to pilocytic astrocytoma WHO grade I, but with an increased mitotic rate, high nuclear pleomorphism, microvascular proliferation, and necrosis. The tumor was subtotally resected and treated with chemotherapy and irradiation. Four years after diagnosis no local progression was seen. At the age of 17, the patient developed a supratentorial primitive neuroectodermal tumor. We report the first case of a primary anaplastic pilocytic astrocytoma and primary primitive neuroectodermal tumor occurring in the same patient.

Second malignant neoplasms following the treatment of brain tumors in children

We investigated retrospectively 992 children with central nervous system tumors who were treated at our center between 1970 and 2004. All of the patients were treated by surgery, chemotherapy, and/or radiotherapy. Six patients developed second malignant neoplasms, and their clinical and histopathologic characteristics are reviewed in this article. The second malignant neoplasms were diagnosed as non-Hodgkin lymphoma, myelodysplastic syndrome, basal cell carcinoma, malignant melanoma, Kaposi sarcoma, and high-grade neuroectodermal tumor. The initial diagnoses were ependymoblastoma in one, medulloblastoma in three, and low-grade astrocytoma in two patients. The median latency time was 3.03 years (range 0.39-22.93 years). The outcome varied according to the histopathologic type of the second tumor. The patients who developed non-Hodgkin lymphoma and myelodysplastic syndrome died of progressive disease. The patients with second skin neoplasms are alive as of the time of this writing. The patient with Kaposi sarcoma developed one of the rare reported second malignant neoplasms following a primary brain tumor in childhood. A wide spectrum of second malignant neoplasms was detected after treatment of primary brain tumors with surgery, radiotherapy, and chemotherapy. Long-term follow-up is therefore necessary for the child who has survived a primary central nervous system tumor.

Very Late Frontal Relapse of Medulloblastoma Mimicking a Meningioma in an Adult: Usefulness of 1H Magnetic Resonance Spectroscopy and Diffusion-perfusion Magnetic Resonance Imaging for Preoperative Diagnosis: Case Report

OBJECTIVE AND IMPORTANCE:

We present a rare case of very long-term medulloblastoma relapse in an adult patient and discuss the pattern of recurrence and metabolic imaging of the tumor.

CLINICAL PRESENTATION:

A 45-year-old man was referred for evaluation of a frontobasal midline tumor 21 years after treatment of a cerebellar medulloblastoma by surgery followed by chemotherapy and craniospinal radiotherapy. Magnetic resonance images were suggestive of a meningioma. Several hypotheses were discussed, such as other radio-induced tumors, sarcomas, high-grade gliomas, or lymphomas (previous chemotherapy) and even recurrence of medulloblastoma. Preoperative exploration included 1H magnetic resonance single-voxel spectroscopy (35 and 135 ms echo time), diffusion imaging, and perfusion magnetic resonance imaging.

INTERVENTION:

On magnetic resonance spectroscopy, N-acetyl-aspartate and an elevated choline/creatine ratio were retrieved, with a huge unidentified peak at 1.27 parts per million (ppm). Myoinositol signal was present at both echo times. On diffusion imaging, the tumor appeared hyperintense, with a low apparent diffusion coefficient value of 0.689. In the perfusion study, the maximal relative cerebral blood volume was 2. Metabolic imaging favored the diagnosis of medulloblastoma over the initially suspected diagnosis of meningioma. The patient underwent complete removal of the tumor that was confirmed to be a metastasis of his primary medulloblastoma. The postoperative course was uneventful, and complementary courses of radiotherapy and chemotherapy were planned.

CONCLUSION:

Late relapse should be considered, even after several decades, on occurrence of a second intracranial tumor in this context. Our observation validates the clinical interest of preoperative metabolic imaging for brain tumors with distinctive pattern.

The Burden of Radiation-Induced Central Nervous System Tumors

Radiation-induced tumors of the central and peripheral nervous systems are becoming a noticeable subset of tumors seen at referral institutions. This paper outlines a single institution s experience with 22 examples of secondary meningiomas, gliomas, and sarcomas that developed in adults. These tumors are being increasingly encountered by physicians, but the greatest burden is on the patients themselves, who not only experience the life-altering effects of the original tumor and the subsequent delayed cognitive effects of radiotherapy, but later develop a second intracranial neoplasm. We detail a particularly poignant example of a 34-year-old man who developed a high-grade sarcoma with rhabdomyosarcomatous and osteogenic elements. Local control was difficult over the next year, and he eventually developed cerebrospinal fluid dissemination and succumbed. Although radiation-induced neoplasm remain relatively infrequent numerically, each case reminds us of the need for new, less toxic, and more targeted therapies for brain neoplasms.

Molecular genetics of supratentorial primitive neuroectodermal tumors and pineoblastoma

The supratentorial primitive neuroectodermal tumors (PNETs) are a group of highly malignant lesions primarily affecting young children. Although these tumors are histologically indistinguishable from infratentorial medulloblastoma, they often respond poorly to medulloblastoma-specific therapy. Indeed, existing molecular genetic studies indicate that supratentorial PNETs have transcriptional and cytogenetic profiles that are different from those of medullo-blastomas, thus pointing to unique biological derivation for the supratentorial PNET. Due to the rarity of these tumors and disagreement about their histopathological diagnoses, very little is known about the molecular characteristics of the supratentorial PNET. Clearly, future concerted efforts to characterize the molecular features of these rare tumors will be necessary for development of more effective supratentorial PNET treatment protocols and appropriate disease models. In this article the authors review existing molecular genetic data derived from human and mouse studies, with the aim of providing some insight into the putative histogenesis of these rare tumors and the underlying transforming pathways that drive their development. Studies of the related but distinct pineoblastoma PNET are also reviewed.

Adult growth hormone replacement therapy and neuroimaging surveillance in brain tumour survivors

OBJECTIVE

Systematic collections of neuroimaging data are nonexistent in brain tumour survivors treated with adult growth hormone replacement therapy (AGHRT). We present our surveillance data.

DESIGN

In 1993, our unit implemented a policy of performing brain scans on every brain tumour survivor before starting AGHRT, with repeat neuroimaging at least once after 12-18 months' treatment. Reports for baseline scans and most recent scans were analysed for this retrospective study.

PATIENTS

All brain tumour survivors who received AGHRT (60 patients) were included in the analysis.

MEASUREMENTS

Evidence and extent of residual tumour, tumour progression, tumour recurrence, and secondary neoplasms (SN) on baseline scan and latest follow-up scan.

RESULTS

All patients had baseline scans performed. Follow-up scans were available in 41/45 (91%) patients who received AGHRT for more than 1 year (mean duration +/- SD of GHRT was 6.7 +/- 3.6 years). Sixteen patients had residual tumours, and SNs (all meningiomas) were demonstrated in three patients on baseline scans. Appearances remained stable in 34 (83%) patients during follow-up (extending to 17.4 +/- 8.3 years after tumour diagnosis). Of the 16 residual primary tumours, an incurable ependymoma continued to grow, and one meningioma progressed slightly in size over 7.7 years. Follow-up scans also revealed continued growth of the SNs detected at baseline, and five additional meningiomas (two in patients with a previous SN, confirming an excess risk in this subgroup, P = 0.02). All SNs occurred on average 22.8 (range 17-37) years after radiotherapy.

CONCLUSIONS

Our data do not suggest an increased rate of recurrence or progression of childhood brain tumours during AGHRT. Nonetheless, vigilance and long-term surveillance are needed in these patients in order to detect and monitor SNs, in particular in patients with a previous history of a SN. We endorse a proactive neuroimaging policy, preferably as part of a larger, controlled trial in the future.

Radiation-induced intracranial meningiomas: review of six operated cases

It is well known that radiation can induce meningiomas. These tumors usually arise in patients with a history of low-dose radiation to the scalp for treatment of tinea capitis or high-dose radiation for a previous brain tumor. Radiation-associated meningiomas (RAMs) morphologically resemble their spontaneously arising counterparts. However, RAMs frequently present a more malignant phenotype and, as such, are diagnosed as "atypical" or "aggressive" meningiomas and occur predominantly in younger patients. This paper describes six cases of radiation-associated intracranial meningiomas in patients previously treated with low-dose radiation to the scalp for tinea capitis.

Second neoplasms in pediatric patients with primary central nervous system tumors

BACKGROUND

Details on second neoplasms (SNs) following pediatric central nervous system (CNS) tumors are scant, because of the rarity of such SNs. The goal of the current study was to investigate and characterize these rare SNs.

METHODS

The authors reviewed clinical and treatment data on all institutional patients age < 22 years at diagnosis of a primary CNS tumor who developed any type of SN. Patients with neurofibromatosis type 1 were excluded. Cumulative incidence rates were estimated, and putative risk factors were analyzed.

RESULTS

The SNs investigated in the current study included 10 gliomas (42%), 5 meningiomas (21%), 2 desmoid tumors, 2 myelodysplastic syndromes, 2 basal cell carcinomas, 1 leukemia, 1 malignant fibrous histiocytoma, and 1 thyroid carcinoma. Twenty-one patients had previously received radiotherapy, and 12 patients had received chemotherapy. The SN was related to a genetic cause in 7 patients (29%). Eleven patients died of their SNs, including 8 patients with glioma and 2 patients with myelodysplastic syndromes. The estimated 15-year cumulative incidence rate for malignant SNs was 4%. Children with choroid plexus tumors had an estimated 10-year cumulative incidence rate of 20.2%; 2 of those patients had germline TP53 mutations. Age </= 2 years was a significant risk factor (P = 0.016) for development of an SN only when patients with genetic conditions were included in the analysis. No significant difference in the estimated cumulative incidence of SNs was found among patients who had received different types of therapy.

CONCLUSIONS

The risk of lethal SNs after pediatric CNS tumors is small. Young patients and patients with choroid plexus tumors appear to have an increased risk of SNs that is associated with genetic factors.