Radiation-induced intracranial malignant gliomas

[Secondary tumors following radiation therapy and chemotherapy : Incidence of cavernous hemangiomas]

PROBLEM

There is a risk of developing secondary central nervous system (CNS) tumors after cranial radiation therapy. Meningiomas and pituitary tumors are also increasingly treated with radiation therapy, which means that the risk of secondary tumors from radiation in children and adults must be communicated.

METHODS

Studies in children show that radiation causes a 7- to 10-fold increase in subsequent CNS tumors with a cumulative incidence over 20 years ranging from 1.03 to 28.9. The latency period for the occurrence of secondary tumors ranged from 5.5 to 30 years, with gliomas developing after 5-10 years and meningiomas around 15 years after irradiation. The latency period for secondary CNS tumors in adults ranged from 5 to 34 years.

CONCLUSION

After radiation treatment, tumors can rarely occur as secondary sequelae, mostly meningiomas and gliomas, but also cavernomas. The treatment and long-term results of radiation-induced CNS tumors showed no worse results than primary CNS tumors over the course of time.

Extraneural Metastasis of Primary Glioma Occurring in a Setting of Occupational Ionizing Radiation Exposure

Malignant gliomas account for 60% of all primary brain tumors in adults. Glioblastoma Multiforme (GBM) is the most common primary glial tumor with a dismal prognosis and a median survival of approximately 14 months. Extra-neural metastases from primary brain tumors are unusual with an incidence rate of less than 2%. This has been attributed to factors such as short survival, lack of true lymphatics in the CNS, and physical barriers provided by the dura, extracellular matrix, and basement membrane. Although most GBMs occur sporadically, there is a known association with therapeutic radiation exposure and with work in nuclear disaster cleanup. To our knowledge, no case of GBM with metastasis occurring in a patient with occupational radiation exposure currently exists in the literature. In this article, we present a case of GBM with lung metastasis occurring in a 51-year-old Caucasian male, whose history is significant for occupational exposure to ionizing radiation, and review the literature on GBM risk factors and potential mechanisms of metastasis.

Post-Radiation Gliomas

Aims and background

Radiotherapy is important in the treatment of neoplasm of the central nervous system, but various side effects, particularly neoplastic, have been described. Recently, post-radiation gliomas have been reported.

Methods

The authors review 88 cases of cerebral glioma following radiotherapy in patients operated for neoplasms of the nervous system, including 6 personal cases of post-radiation gliomas treated in the Neurosurgical Division of the Department of Neurological Sciences, “La Sapienza” University, Rome. The criteria used to define this unusual pathologic association are discussed.

Results

There was a male predominance. Post-radiation gliomas were particularly malignant, the average dose was 33 Gy, and average free latency was 9.6 years. The first disease was most frequently acute lymphatic leukemia.

Conclusions

Post-radiation gliomas have particular features but do not present a histologic or clinical behavior different from analogous spontaneous gliomas. The fact that 88 cases have been reported in recent years suggests that a thorough biological, clinical studies be carried out on this association.

Three case reports of radiation-induced glioblastoma after complete remission of acute lymphoblastic leukemia

Radiation therapy is sometimes performed to control intracranial acute lymphoblastic leukemia (ALL), but may lead to radiation-induced malignant glioma. The clinical, radiological, histological, and molecular findings are described of three cases of radiation-induced glioblastoma after the treatment for ALL. They received radiation therapy at age 6-8 years. The latency from radiation therapy to the onset of radiation-induced glioblastoma was 5-10 years. Magnetic resonance imaging demonstrated diffuse lesions with multiple small enhanced lesions in all cases. Histological examination showed that the tumors consisted of mainly small round astrocytic atypical cells in one case, and astrocytic atypical cells with elongated cytoplasm and nuclear pleomorphism with small cell component in two cases. Microvascular proliferation was present in all cases. Immunohistochemical analysis for B-Raf V600E, and mutational analysis for the isocitrate dehydrogenase (IDH) 1, IDH2, and H3F3A gene revealed the wild-type alleles in all three cases. The integrated diagnoses were IDH wild-type glioblastoma, and local irradiation and concomitant temozolomide were performed. After the initial treatment, significant shrinkage of the diffuse lesion and enhanced lesion was found in all cases. Radiation-induced glioblastoma occurring after the treatment for ALL had unique clinical, radiological, histological, and molecular characteristics in our three cases.

Secondary Intracranial Tumors Following Radiotherapy for Pituitary Adenomas: A Systematic Review

Pituitary adenomas are often treated with radiotherapy for the management of tumor progression or recurrence. Despite the improvement in cure rates, patients treated by radiotherapy are at risk of development of secondary malignancies. We conducted a comprehensive literature review of the secondary intracranial tumors that occurred following radiotherapy to pituitary adenomas to obtain clinicopathological characteristics. The analysis included 48 neuroepithelial tumors, 37 meningiomas, and 52 sarcomas which were published between 1959–2017, although data is missing regarding overall survival and type of irradiation in a significant proportion of the reports. The average onset age for the pituitary adenoma was 37.2 ± 14.4 years and the average latency period before the diagnosis of the secondary tumor was 15.2 ± 8.7 years. Radiotherapy was administered in pituitary adenomas at an average dose of 52.0 ± 19.5 Gy. The distribution of pituitary adenomas according to their function was prolactinoma in 10 (7.2%) cases, acromegaly in 37 (27.0%) cases, Cushing disease in 4 (2.9%) cases, PRL+GH in 1 (0.7%) case, non-functioning adenoma in 57 (41.6%) cases. Irradiation technique delivered was lateral opposing field in 23 (16.7%) cases, 3 or 4 field technique in 27 (19.6%) cases, rotation technique in 10 (7.2%) cases, radio surgery in 6 (4.3%) cases. Most of the glioma or sarcoma had been generated after lateral opposing field or 3/4 field technique. Fibrosarcomas were predominant before 1979 (p < 0.0001). The median overall survival time for all neuroepithelial tumors was 11 months (95% confidence intervals (CI), 3–14). Patients with gliomas treated with radiotherapy exhibited a non-significant positive trend with longer overall survival. The median overall survival time for sarcoma cases was 6 months (95% CI, 1.5–9). The median survival time in patients with radiation and/or chemotherapy for sarcomas exhibited a non-significant positive trend with longer overall survival. In patients treated with radiotherapy for pituitary adenomas, the risk of secondary tumor incidence warrants a longer follow up period. Moreover, radiation and/or chemotherapy should be considered in cases of secondary glioma or sarcoma following radiotherapy to the pituitary adenomas.

A case of multiple radiation-induced gliomas 24 years after radiation therapy against pituitary adenoma

We treated a case in which multiple astrocytomas of varying grades developed in the irradiation field 24 years after radiation therapy. Differentiation from radiation necrosis based on presurgical diagnostic imaging was difficult; therefore, we feel it is essential to aggressively pursue histological diagnoses to select the optimal treatment method.

Malignant Astrocytoma of the Optic Nerve in a Child

Malignant gliomas of optic nerve and chiasm are rare, rapidly fatal neoplasms of adulthood. This report documents the occurrence of a malignant astrocytoma of the optic nerve in an 11-year-old boy who 9 years previously had a cerebellar medulloblastoma treated with surgery and irradiation. This malignant optic nerve glioma followed the same aggressive clinical course as that seen in adults, with death 9 months after diagnosis despite surgery and chemotherapy: Radiation may have been an important factor in the development of this malignant tumor which is almost never seen in the pediatric age group.

An early and rare second malignancy in a treated glioblastoma multiforme: is it radiation or temozolomide?

Glioblastoma Multiforme (GBM) is a high-grade brain tumour with the most dismal prognosis. There are very few reports on second malignancies occurring in GBM patients, as the survival has been short. Second malignancies have been reported after treatment of malignancies with radiation therapy and chemotherapy especially after 5 to 10 y of treatment. Here in, we present a very unique case where a patient succumbed to sinonasal carcinoma occurring one and half years after treatment of GBM. A 17-year-old boy was diagnosed to have GBM and underwent surgery followed by chemoradiation and adjuvant chemotherapy with Temozolamide. He presented with undifferentiated sinonasal carcinoma, in the sinonasal region outside the radiation field within two years of treatment. Here we discuss the histology and possible chances of it being a second malignancy.

Therapy-associated secondary tumors in patients with non-germinomatous malignant germ cell tumors

We report three patients with non-germinomatous malignant germ cell tumor (NGMGCT) who developed therapy-associated secondary tumors. They were diagnosed as having NGMGCT by elevated serum levels of α-fetoprotein (AFP), human chorionic gonadotropin (HCG), or β-HCG. Preoperatively, all patients received a combination of etoposide and platinum-based chemotherapy and radiotherapy; neo-adjuvant therapy (NAT) was followed by complete excision of the residual tumor. Postoperatively, all underwent maintenance chemotherapy and all remained free of NGMGCT without recurrence. However, they developed therapy-associated secondary tumors, i.e. glioblastoma, meningioma, or cavernous angioma after 10.1, 9.8, and 8.2 years, respectively. The patient with glioblastoma died one year after its detection. The other two patients are currently alive; the meningioma was completely removed and the cavernous angioma is being monitored without additional treatment. To the best of our knowledge, therapy-associated secondary tumors in patients treated for NGMGCT are rare.

Secondary gliosarcoma: a review of clinical features and pathological diagnosis

OBJECT

Although secondary gliosarcoma after treatment of primary glioblastoma multiforme has been described, little is known of these rare tumors. In this article the authors review the literature on secondary gliosarcoma, with attention to clinical course and pathological features.

METHODS

A PubMed search of the key word intracranial "gliosarcoma" with and without "radiation" or "radiotherapy" in humans was performed. The 204 citations yielded were screened for relevancy to gliosarcomas that occur after treatment of previous intracranial neoplasms.

RESULTS

A search of the literature yielded 24 relevant articles, combined for a total of only 12 cases of secondary gliosarcoma and 12 cases of radiation-induced gliosarcoma. Of the 12 cases of secondary gliosarcoma, all were previously treated with surgery and radiotherapy (mean dose 50.7 Gy), with a mean survival of 13 months since time of gliosarcoma diagnosis (range 6.9-19.4 months). In the cases of radiation-induced gliosarcoma, the mean dose of previous radiotherapy was 51.3 Gy (median 54 Gy, range 24-60 Gy), and the mean survival since gliosarcoma diagnosis was 6.7 months (median 6 months, range 2-10 months).

CONCLUSIONS

Secondary gliosarcoma and radiation-induced gliosarcoma are exceedingly rare. The literature on secondary gliosarcoma illustrates a more favorable survival than for primary gliosarcoma but remains limited regarding clinical and radiographic presentation, response to treatment, and pathogenesis. The results of the present review also support the notion that secondary gliosarcomas and radiation-induced gliosarcomas are distinct entities, with longer survival and shorter latency of gliosarcoma induction seen in the former. Efforts to elucidate the role of radiotherapy in the induction of gliosarcomas may yield new insights into therapeutic risks of cranial radiation and CNS tumor pathogenesis.

Intracranial malignancies occurring more than 20 years after radiation therapy for pituitary adenoma

A 37-year-old woman developed a left third cranial nerve palsy 28 years after radiation for a nonsecreting pituitary adenoma. Imaging disclosed a left parasellar mass and a midbrain/pontine signal abnormality. Biopsy of the parasellar mass revealed a malignant sarcoma. The brainstem abnormality was presumptively diagnosed as a malignant glioma. A 63-year-old man developed a malignant astrocytoma of the left optic nerve and chiasm 23 years after partial excision and radiation of a nonsecreting pituitary adenoma. Both patients died of their malignancies. Although secondary malignancies have been described in this setting, such long latencies have not been reported.

Rapid growth of primary cerebral fibrosarcoma with conversion to glioblastoma at second recurrence

We present a case of de novo fibrosarcoma in a 43-year-old male, with MRI documented evolution from a 5 mm hyperintense area to 5 cm tumor mass in a 12-month period. The diagnosis of low-grade fibrosarcoma was established by three experienced neuropathologists. The patient underwent gross total resection with adjuvant fractionated conformal radiotherapy. Following first recurrence 3 months later, the patient was reoperated and stereotactic radiosurgery of a residual tumor was performed thereafter. The pathological diagnosis was similar, but with additional extensive radiation effects. Six months later the patient underwent aggressive surgical resection for second recurrence. The pathological diagnosis was WHO grade IV glioblastoma. The etiology of this highly unusual progression from primary mesenchymal neoplasm to high-grade glioma is discussed.

Two metachronous tumors induced by radiation therapy: case report and review of the literature

Various radiation-induced tumors, including meningioma, glioma, and sarcoma, have been reported; however, metachronous intracranial double tumors induced by radiation therapy are extremely rare. A 1-year-old boy had undergone tumor removal and craniospinal radiation therapy (30 Gy) for cerebellar medulloblastoma. At 24 years old, parasagittal meningioma developed in the left parietal region and was totally removed. Six years later, an infiltrative tumor was newly found in the right fronto-temporal white matter. The patient underwent stereotactic biopsy, and the tumor was found to be an anaplastic astrocytoma. Chromosomal analysis by fluorescence in situ hybridization (FISH) revealed loss of heterozygosity (LOH) of 1p. As the patient had previously had craniospinal irradiation, no additional radiation therapy was delivered. He underwent chemotherapy with temozolomide and the disease is now stable. Since both secondary tumors were located within the area of previous radiation and the patient did not have any genetic disease predisposing him to tumors, radiation therapy was considered to be responsible for their tumorigenesis. To our knowledge, this case is the fourth case of radiation-induced double CNS tumors arising after radiotherapy to be described in the literature. Whenever radiation is administered to children or young adults, careful serial screening studies are needed.

Radiation-induced malignant gliomas: is there a role for reirradiation?

PURPOSE

To review the literature regarding the role of radiotherapy (RT) in the treatment of patients with radiation-induced malignant gliomas (RIMGs).

METHODS AND MATERIALS

A PubMed search of English-language articles dealing with RIMG was performed, yielding 52 articles with 92 patients available for review.

RESULTS

Initial tumor types treated with RT included brain tumor in 37 patients (40%), acute lymphoblastic leukemia in 33 (36%), benign disease in 11 (12%), and other in 11 (12%). Median time from RT to development of an RIMG was 8.75 years (range, 2.5-61 years). The RIMG occurred within 10 years after RT in 81% of patients with acute lymphoblastic leukemia/lymphoma, 59% of patients with brain/other, and 18% of patients with benign conditions (p = 0.002). Type of RIMG was glioblastoma in 69 (75%) and anaplastic astrocytoma in 23 (25%). One-, 2-, and 5-year overall survival rates were 29.3%, 7.3%, and 0% for patients with glioblastoma and 59.7%, 30.3%, and 20.2% for patients with anaplastic astrocytoma. For the 85 patients with data regarding treatment for RIMG, 35 underwent reirradiation to a median dose of 50 Gy (range, 30-76 Gy). For patients undergoing reirradiation, 1-, 2- and 5-year overall survival rates were 58.9%, 20.5%, and 6.8%. For those not undergoing reirradiation, they were 15.1%, 3%, and 0% (p = 0.0009).

CONCLUSIONS

The RIMG appeared earlier in patients treated for leukemia and lymphoma and latest for those treated for a benign condition. Patients who underwent reirradiation for RIMG have longer survival times compared with those not receiving RT.

A review: dietary and endogenously formed N-nitroso compounds and risk of childhood brain tumors

Maternal dietary exposure to N-nitroso compounds (NOC) or to their precursors during pregnancy has been associated with risk of childhood brain tumors. Cured meat is one source of exposure to dietary NOC and their precursors. Most epidemiological studies that have examined the role of maternal consumption of cured meats during pregnancy have found a significant positive association between maternal intake of cured meat and the risk of childhood brain tumor (CBT). NOC consist of two main groups, N-nitrosamines and N-nitrosamides. The carcinogenicity profiles of NOC suggest that N-nitrosamides rather than N-nitrosamines are the compounds that may be associated with CBT and that they should be investigated more closely in epidemiological studies. We present a review of the chemical and carcinogenic properties of NOC in connection with the findings of case-control studies. This approach may be helpful in determining the essential information that must be collected in future epidemiological studies on CBT.

Response to chemotherapy of a radiation-induced glioblastoma multiforme

BACKGROUND

Radiation-induced glioblastoma multiforme (GBM) is particularly resistant to treatment and therapeutic options are limited. We report a patient with a radiation-induced GBM who had a complete response to carmustine and survived for 44 months.

PATIENTS AND METHODS

Case report of a 38-year-old man with a radiation-induced GBM that responded to carmustine.

RESULTS

Our patient developed a left occipital GBM 35 years after a left cerebellar astrocytoma was treated with surgery and radiation therapy (4500 rad). The GBM was treated with subtotal resection followed by four cycles of carmustine; a complete response was achieved. He relapsed 34 months after diagnosis and with further surgery survived 44 months from his diagnosis of GBM.

CONCLUSION

GBMs may be a late complication of radiation treatment for pediatric brain tumors. If further radiotherapy is not a therapeutic option, chemotherapy may result in prolonged survival.

Microdissection genotyping of mixed glial and primitive neuroectodermal central nervous system neoplasm

A 22-year-old man with previous radiation treatment for childhood astrocytoma underwent resection of a right parietooccipital lesion. Histopathology revealed a malignant neoplasm with areas of astrocytic and primitive neuroectodermal components. To resolve the relationship and cellular origin, representative tissue was microdissected from several targets, obtaining a balanced mixture of each element. Nonneoplastic brain parenchyma was separately microdissected to determine polymorphic marker informativeness and to serve as an internal negative control. Despite the relatively small quantity of tissue removed for each microdissection target, sufficient material was available for reliable, balanced, polymerase chain reaction-format genotyping encompassing a panel of tumor suppressor genes and genetic loci associated with these forms of neoplasia. The findings revealed distinct discordant genotypic profiles for each of the neoplastic components. The efficacy of the approach used for molecular analysis of this complex neoplasm and the implication of the genotypic findings are discussed.

Gliosarcoma with osteosarcomatous differentiation: review of radiological and pathological features

Gliosarcoma is a rare tumor of the central nervous system, consisting of gliomatous and sarcomatous elements. We present an unusual case of gliosarcoma which demonstrated a variation in phenotype over a six month period, changing from a gliosarcoma with osteosarcomatous differentiation, to a gliosarcoma with no osteosarcomatous component. The initial histological diagnosis was glioblastoma multiforme. Fifteen months later the tumor had transformed into a gliosarcoma demonstrating osteosarcomatous differentiation, with the majority of the tumor consisting of osteoid matrix. Further samples taken six months later revealed gliosarcoma with almost no osteosarcomatous component. It is recognized that glioblastoma can undergo a change in phenotype, transforming into a gliosarcoma. This case demonstrates that ongoing changes in phenotype can occur, especially when the tumor has been treated with chemotherapy and radiotherapy. An understanding of the pathological progression of gliosarcoma will become increasingly important as novel treatments for gliosarcoma and glioblastoma become available.

Radiation-induced gliomas: report of 10 cases and review of the literature

BACKGROUND

Radiotherapy and more recently radiosurgery represent important therapeutic methods for the treatment of tumors and arterovenous malformations affecting the central nervous system, even though several significant side-effects have been described (radionecrosis, tumors, etc.). Gliomas induced by radiation therapy are decidedly unusual, and the first descriptions of this association only appeared in the 1960s.

METHODS

The pertinent literature was reviewed to yield 116 cases in which a glioma developed after radiotherapy for cranial pathologies (included 10 personal cases treated in our Institution). One of our patients had undergone radiosurgery for a cavernous angioma.

RESULTS

Patients who developed a radiation-induced glioma were younger, as a group, than those affected with so-called "spontaneous" gliomas. The tumor originated in the previously irradiated area, after average doses of 32 Gy and an average latency period of 9.6 years in accordance with the findings reported by the authors and in our experience as well. Radiotherapy had most frequently been performed for acute lymphoblastic leukemia. Our Case 10 is the fourth case of intracranial tumor arising after radiosurgery to be described in the literature.

CONCLUSIONS

Though rare, gliomas may represent a late complication of radiation treatment. The behavior of the radiation-induced variety of glioma does not seem to differ significantly from that of its "spontaneous" counterpart. Late complications of the radiosurgery are probably underestimated because of the relatively recent introduction of this technique. On the contrary, these should be scrupulously evaluated when deciding whether to employ this method for therapeutic purposes for relatively benign or congenital lesions (which generally affect young patients with a long life expectancy).

Stereotactic radiosurgery for meningiomas

Meningiomas are benign tumors attached to the dura that typically have a slow growth rate. After gliomas, they are the most common primary tumor of the brain. They are ideal radiobiological targets because single-fraction radiation has a high biologically effective dose. Furthermore, a highly conformal radiation plan can provide effective treatment to the tumor while sparing the surrounding brain. Meningioma control rates range from 90 to 95%, and the risk of morbidity is low. Radiosurgery is an excellent treatment for asymptomatic, small- to moderate-sized meningiomas. It is also ideal for patients with incompletely resected meningiomas, recurrent meningiomas, and risk factors precluding conventional surgery.

Radiation-induced glioma presenting as diffuse leptomeningeal gliomatosis: a case report

BACKGROUND

Leptomeningeal gliomatosis is a rare and fatal disease.

METHODS

Case report.

RESULTS

We report the case of a man who was presented with severe intractable headaches, lymphocytic CSF pleocytosis, and spinal leptomeningeal enhancement on contrast MRI. Meningeal biopsy demonstrated diffuse infiltration by malignant glial cells, and symptom alleviation was achieved by CSF diversion. He later developed an enhancing thalamic tumor arising within the treatment field of a remotely irradiated pituitary adenoma. Subsequent management included chemotherapy and further radiotherapy with transient response, before death from leptomeningeal and parenchymal tumor progression 16 months after diagnosis.

CONCLUSION

We report a unique case embodying two rare conditions: radiation induced glioma and leptomeningeal gliomatosis. Our patient's course is novel in that symptomatic relief was achieved with CSF diversion and a combination of chemotherapy and focal radiation allowed prolonged survival.

Radiosurgery-induced brain tumor. Case report

The authors describe a case of glioblastoma multiforme (GBM) associated with previous gamma knife radiosurgery for a cerebral arteriovenous malformation (AVM). A 14-year-old boy had undergone radiosurgery for an AVM, which was performed using a 201-source 60Co gamma knife system at another institution. The maximum and margin radiation doses used in the procedure were 40 and 20 Gy, respectively. One year after radiosurgery, the patient noticed onset of mild left hemiparesis due to radiation necrosis. Six and one-half years after radiosurgery, at the age of 20 years, the patient experienced an attack of generalized tonic-clonic seizure. Magnetic resonance (MR) imaging revealed the existence of a brain tumor in the right parietal lobe. The patient underwent an operation and the histological diagnosis of the lesion was GBM. Ten months following the operation, that is, 99 months postradiosurgery, this patient died. To the best of the authors' knowledge, this is the first reported case of a neoplasm induced by radiosurgery for an AVM and the second case in which it occurred following radiosurgery for intracranial disease.

Second cancers in patients with brain tumours--impact of treatment

The records of the Finnish Cancer Registry from 1953 to 1994 were used to assess the risk of subsequent primary cancer among 14,493 brain tumour patients. They had been treated with surgery only (n = 9804), radiotherapy (n = 4099), chemotherapy and radiotherapy (n = 493) or chemotherapy alone (n = 97). By the end of 1994, 403 subsequent primary cancers were registered in these patients, whilst the expected number based on national incidence was 332. The standardised incidence ratio (SIR) was 1.2 (95% confidence interval (CI) 1.1-1.3). A significant excess risk of tumours in the central nervous system (CNS) including meningeomas (SIR 2.6, 95% CI 1.7-3.8), non-Hodgkin's lymphoma (SIR 2.6, 95% CI 1.6-4.1) and skin melanoma (SIR 1.9, 95% CI 1.0-3.1) was observed. CNS tumours were observed in excess among patients treated with surgery alone (SIR 2.0, 95% CI 1.2-3.2) and with radiotherapy (SIR 5.1, 95% CI 2.5-9.4). In conclusion, brain tumours are associated with an increased risk of both CNS second tumours and non-CNS second cancers, especially non-Hodgkin's lymphoma and melanoma. A moderately increased risk of second tumours in the CNS was observed among brain tumour patients treated with surgery only and a larger excess among those treated with radiotherapy.

Malignant cerebellar astrocytoma developing 15 years after radiation therapy for a medulloblastoma

A case of malignant cerebellar astrocytoma occurring 15 years after the radiation therapy for a medulloblastoma is reported. The tumor developed at the same site of irradiation after a sufficient latent period and was completely different from medulloblastoma in its histology. This tumor fulfilled the criteria of radiation-induced neoplasm. Only seven similar cases have been reported up to the present. Whole neuraxis irradiation following a gross total resection is a standard treatment for medulloblastoma, but the possibility of the development of radiation-induced tumors must be borne in mind for a long time after the radiation therapy for medulloblastoma.

Glioma occurrence after sellar irradiation: case report and review

OBJECTIVE

Tumor neogenesis is an uncommon but known consequence after therapeutic irradiation of the central nervous system. Causative agents for glioma induction remain unknown, but laboratory and clinical data suggest a possible role for radiation as a promotor. In the treatment of both pituitary adenomas and craniopharyngiomas, adjunctive conventional radiation therapy has long played a role.

CLINICAL PRESENTATION

This report details two cases in which patients received standard sellar irradiation for growth hormone-secreting pituitary adenomas and later were diagnosed with gliomas, after a latency period of 11 and 18 years, respectively. Additionally, a comprehensive review of the literature with 30 reports of gliomas developing after conventional radiation for treatment of pituitary adenomas and craniopharyngiomas is presented. The mean dose for craniopharyngiomas (n = 8) was 5800 cGy, with a mean latency of 11.5 years from initial diagnosis to the eventual discovery of the gliomas. The mean dose for the treatment of pituitary adenomas (n = 24) was 5300 cGy, with a mean latency of 10.4 years.

CONCLUSION

Typical features of the resulting gliomas included presentation in young patients, histologically high grades, and occurrence within the temporal lobe. A large proportion of gliomas were associated with growth hormone-secreting adenomas. This review assesses the implication of doses of conventional radiotherapy that were previously thought to be benign and concludes that although radiation-associated gliomas are uncommon, they represent a potentially devastating long-term risk. Based on this analysis, treatment of sellar tumors with conventional fractionated radiotherapy should be carefully considered and perhaps used primarily in those cases for which radiosurgery is not appropriate.

Late sequelae of treated pleomorphic xanthoastrocytoma: malignant brain stem astrocytoma occurring 15 years after radiation therapy

The pleomorphic xanthoastrocytoma (PXA) is a unique astrocytic neoplasm with an unexpectedly favorable prognosis despite striking pleomorphism of the cellular constituents. Although a majority of patients experience extended survival, these tumors may recur and some cases progress to high-grade astrocytoma. Recurrence inevitably involves the anatomic vicinity of the primary tumor. In this report, we describe a malignant brain stem astrocytoma that occurred 15 years after surgery and radiation treatment of a 16-year-old patient who had a temporal lobe PXA. To our knowledge, this is the first reported case of a malignant astrocytoma arising outside the primary anatomic site of a previously treated PXA and likely represents a radiation-induced secondary neoplasm.

Radiation-induced gliosarcoma. Case report and review of the literature

A 13-year-old boy presented with a cerebral gliosarcoma 12 years after having acute lymphoblastic leukemia treated by chemotherapy and central nervous system prophylaxis treated by radiation therapy (24 Gy) and intrathecal methotrexate. A review of the literature disclosed 129 possible radiation-induced gliomatous and/or sarcomatous brain tumors: namely, 89 gliomas, 36 sarcomas, and four gliosarcomas, including the present case. An analysis of these cases revealed several characteristics that differentiate them from similar spontaneous brain tumors, thus providing arguments for the carcinogenic effect of radiation therapy on intracranial tumors.

Clinicopathologic features of primary and postirradiation cerebral gliosarcoma

BACKGROUND

Gliosarcoma is an uncommon malignant brain tumor with mixed glial and mesenchymal elements. Experience is limited to case series, and pathologic data are disparate, leading to uncertainty about clinical features, management, and histogenesis.

METHODS

A clinicopathologic review of 32 patients with survival analysis and immunohistochemical studies was performed including glial fibrillary acidic protein analysis, alpha-1-antitrypsin (alpha-1-AT) analysis, and smooth muscle actin (SMA) analysis.

RESULTS

Twenty-five patients had primary gliosarcoma, whereas 7 developed gliosarcoma after irradiation for glioblastoma multiforme (GBM). Clinical features were similar to those of GBM. Most tumors were intraaxial and diffusely infiltrating by radiologic studies and at surgery. Median survival for primary gliosarcoma was 25 weeks overall, with patients who received irradiation surviving longer (46 vs. 13 weeks, P < 0.025). Gliosarcoma occurring after irradiation appeared hyperdense by computed tomography in five of seven cases, and median survival was 53 weeks. Primary gliosarcoma was a dimorphic tumor with malignant glial elements and features of malignant fibrous histiocytoma (MFH) or fibrosarcoma and one osteosarcoma. Smooth muscle actin labeled tumor vessels heavily, but in 15/25 primary cases, it extended to the surrounding spindle cells. The remaining cases appeared morphologically like MFH and tended to be positive for alpha-1-AT. Postirradiation gliosarcoma was fibrosarcomatous with positive SMA in 75% of the cases examined.

CONCLUSIONS

Gliosarcoma behaves clinically like GBM, and survival may be improved by cranial irradiation of selected patients. Smooth muscle actin reactivity in sarcomatous areas suggests histogenesis in some tumors from the smooth muscle within GBM, whereas others may arise via different mechanisms including differentiation from a pluripotential precursor. Transformation of the smooth muscle within GBM may have therapeutic implications for antiangiogenesis agents.

Radiation necrosis or glioma recurrence: is computer-assisted stereotactic biopsy useful?

Fifty-one patients with supratentorial glioma treated with external beam radiotherapy (median dose 59.5 Gy) who then demonstrated clinical or radiographic evidence of disease progression underwent stereotactic biopsy to differentiate tumor recurrence from radiation necrosis. The original tumor histological type was diffuse or fibrillary astrocytoma in 21 patients (41%), oligodendroglioma in 13 (26%), and oligoastrocytoma in 17 (33%); 40 tumors (78%) were low-grade (Kernohan Grade 1 or 2). The median time to suspected disease progression was 28 months. Stereotactic biopsy showed tumor recurrence in 30 patients (59%), radiation necrosis in three (6%), and a mixture of both in 17 (33%); one patient (2%) had a parenchymal radiation-induced chondroblastic osteosarcoma. The tumor type at stereotactic biopsy was similar to the original tumor type and was astrocytoma in 24 patients (47%), oligodendroglioma in eight (16%), oligoastrocytoma in 16 (31%), unclassifiable in two (4%), and chondroblastic osteosarcoma in one patient (2%). At biopsy, however, only 19 tumors (37%) were low grade (Kernohan Grade 1 or 2). Subsequent surgery confirmed the stereotactic biopsy histological findings in eight patients. Follow-up examination showed 14 patients alive with a median survival of 1 year for the entire group. Median survival times after biopsy were 0.83 year for patients with tumor recurrence and 1.86 years for patients with both tumor recurrence and radionecrosis; these findings were significantly different (p = 0.008, log-rank test). No patient with radiation necrosis alone died. Other factors associated with reduced survival were a high proportion of residual tumor (p = 0.024), a low proportion of radionecrosis (p < 0.001), and a Kernohan Grade of 3 or 4 (p = 0.005). In conclusion, in patients with previously irradiated supratentorial gliomas in whom radionecrosis or tumor recurrence was clinically or radiographically suspected, results of stereotactic biopsy could be used to differentiate tumor recurrence, radiation necrosis, a mixture of both lesions, or radiation-induced neoplasm. In addition, biopsy results could predict survival rates.

Malignant hemispheric tumors in childhood

Sixty-four malignant hemispheric tumors in children less than 15 years old were treated in the pediatric neurosurgical department of the Hôpital des Enfants Malades between 1970 and 1989. (1) These tumors evolved rapidly in most cases. However the pre-operative evolution in 20% of the patients had a duration of more than 6 months, which favors the hypothesis that at least one-fifth of these tumors result from malignant transformation of a benign lesion. This observation should prompt neurosurgeons to operate on all benign hemispheric tumors as soon as they are diagnosed. (2) Five of the 64 patients had two successive malignant diseases. In four cases the other malignant disease was an acute lymphoblastic leukemia. (3) Among the malignant hemispheric tumors, the grade III and IV astrocytomas had a dismal prognosis. As it is known from previous studies that grade I and II astrocytomas have a good prognosis in children, it can be concluded that grading these tumors is essential. By contrast, almost one out of two patients with malignant ependymoma was alive 5 years after treatment. This implies that the grading of ependymomas is of modest prognostic values. (4) The harmful effect of radiotherapy was evaluated by comparing the functional outcome of children operated for a benign hemispheric tumor to that of children operated and irradiated for a malignant hemispheric tumor.

Supratentorial ependymomas of the first two decades of life. Long-term follow-up of 20 cases (including two subependymomas)

In order to better elucidate the lesser known aspects of the biological behavior and prognosis of supratentorial ependymomas in children and young adults, we studied a series of 20 patients, ages 1 to 20 years. The tumor site was extraventricular in 14 cases and intraventricular in 6 (including one third ventricle tumor). Histologically, according to World Health Organization criteria, there were 12 ependymomas (E), 2 subependymomas (SE), and 6 malignant ependymomas (ME). Of the 18 patients surviving surgery, 12 (66.6%) are alive and disease free 63 to 252 months (mean, 146 mo) after the operation; 9 harbored an E, 2 had an SE and 1 had an ME. Four patients are now out of risk of recurrence according to Collin's law. Six of the long-term survivors (50%), four E and two SE, did not receive postoperative radiotherapy. However, two patients with E, initially treated by surgery alone, had a recurrence and one subsequently died. Two ME patients showed signs of spinal metastases after subsequent operation for recurrence and shortly before death. Considering the partially good results as well as failures after surgery alone in our and in other series and the risks of irradiating the child's brain, we tried to elucidate in what cases radiotherapy could be reasonably withheld, or alternatively, when prophylactic craniospinal irradiation should be prescribed. The main conclusions of our study are the following: 1) Radical surgery alone is a reasonable option as the initial treatment for lateral ventricle tumors and for solid extraventricular tumors located far from eloquent brain areas, provided the histology is benign, especially if of the SE type.(ABSTRACT TRUNCATED AT 250 WORDS)

Brainstem glioma after radiation therapy for acute myeloblastic leukemia in a child with Down syndrome. Possible pathogenetic mechanisms

A 13-year-old boy with Down syndrome (DS) had a brainstem glioma confirmed at autopsy, 10 years after receiving prophylactic cranial irradiation for acute myeloblastic leukemia. There is no clear association of brain tumors with DS; despite a reported link between leukemia and glioma, a causal association with radiation therapy is more likely.