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.

Intracranial Meningiomas Developing at Long Intervals Following Low-Dose X-Ray Irradiation of the Head

Five patients are reported who underwent X-ray epilation in childhood for tinea capitis and who developed meningiomas after about four decades. X-ray irradiation resulted in permanent alopecia in four of the five patients. In four patients the tumors were found on the convexity, one patient had a tuberculum sellae meningioma. All five patients underwent surgery. Recurrence was noted in three of the five patients, one of them was reoperated. No malignant features, but signs of atypia were found at histopathological examination. The development of meningiomas after low-dose irradiation with long latency periods, the predominant calvarial location of the tumors, the high recurrence rates, the absence of malignant traits but the presence of atypias are features overwhelmingly common with similar cases published in the literature. The fact that two of the five patients were sisters stresses the importance of genetic factors in the evolution of these tumors.

Carcinomes basocellulaires du cuir chevelu secondaires à une radiothérapie pour teigne : une série de 33 malades

Occurrence of basal cell carcinoma (BCC) following radiotherapy for tinea capitis is well known. The aim of this study was to specify the clinical and histological features of these BCC seen in 33 patients (1995-2000). Twenty seven men and six women were diagnosed with BCC. The age of onset varied between 32 an 62 years. Radiotherapy was received between 5 and 17 years of age. The interval between irradiation and the onset of carcinoma varied between 21 and 51 years. Total number of lesions was 55. Forty percent of BCC occurred on the occipital area, the number varied from 1 to 5 and the size from 2 to 45 mm. Clinically, the nodular type was found in 51% of cases. Pigment was present in 64% of cases. Histological study showed a nodular aspect in 76% and pigmentation in 63% of cases. Nodular and pigmented type were the predominant BCC occurring after radiotherapy for tinea capitis in our series. In the literature, BCC are the most frequent carcinomas occurring after radiotherapy (70-100%). Pigmentation was not described in other series. The nodular histological form was the most frequent.

Ret/PTC activation in benign and malignant thyroid tumors arising in a population exposed to low-dose external-beam irradiation in childhood

Ionizing radiation is the strongest risk factor known for the development of thyroid neoplasia. Although ret/PTC rearrangements have been identified in both spontaneous and radiation-induced papillary thyroid cancer, they seem more frequent among radiation-associated tumors. We studied the frequency of ret/PTC activation in a group of sporadic and radiation-induced thyroid carcinomas (n = 49) and adenomas (n = 13) among 44 individuals treated for Tinea Capitis with low-dose external irradiation as well as in 18 nonirradiated subjects. Total RNA recovered from paraffin-embedded thyroid cancer surgical specimens was analyzed for ret/PTC 1, 2, and 3 mutations using RT-PCR with Southern blotting to maximize detection sensitivity. Ret/PTC rearrangements were identified in 42.9% of thyroid carcinoma and 46.2% of adenoma subjects. Among the positive carcinoma specimens, three were follicular carcinomas. Ret/PTC 1, the predominant rearrangement, was more prevalent in nonirradiated compared with irradiated carcinomas (66.7 vs. 27.0%; P = 0.04). Ret/PTC activation was associated with male gender. The strengths of this study included analysis of age-, gender-, and ethnicity-matched groups; molecular analysis using two techniques; and a complete blinding of laboratory analysis from clinical features. The differences seen between these and other published results may be related to differences in radiation doses to the thyroid, latency period between time of radiation exposure and development of clinically apparent thyroid cancer, and ethnic background of the study populations.

Radio-induced malignancies of the scalp about 98 patients with 150 lesions and literature review

INTRODUCTION

- The induction of malignant diseases is one of the most concerning late effects of ionizing radiation. The topic of this study deals with skin tumors developed in the irradiated areas in children given X-ray therapy for tinea capitis.

MATERIAL AND METHODS

- All patients with malignant tumors of the scalp referred to Salah Azaiz Institute between 1970 and 2001 have been questioned in order to determine if there had been a prior X-ray irradiation for tinea capitis, its modality, and its consequences. The first scalp irradiation goes back to 1922 and the last was performed in 1963.

RESULTS

- Ninety-eight patients with 150 radio-induced cancers of the scalp following irradiation for tinea capitis are reported (1.5 lesion per patient). The patients were irradiated in various hospitals and dispensaries throughout the country. Eighty-one patients (82%) had only one session of radiation. The average age at irradiation was 12 (+/-6) years, the latent period for radiation-induced skin cancers was 36 (+/-14) years. In 61 patients (62%), the scalp appeared normal and in 38% radiodermatitis was noted. Patient age at diagnosis of malignancy varied from 20 to 83 years with an average of 47 years. Basal cell carcinomas (125 cases) and spinocellular carcinomas (16 cases) were the most common, three other cases of annexial tumors, two malignant non-Hodgkin's lymphomas and four melanoma lesions are also present. Radiotherapy was used for the treatment of 74 patients (alone in 42 and associated with surgery in 32 patients); 14 patients had exclusive surgical excision.

CONCLUSIONS

- Basal cell carcinomas are the most frequent tumors arising on chronic radiodermatitis. In spite of the long latency period, patients' young age at irradiation explained the occurrence of these cancers at a relatively young age. Literature review is suggesting recessive mutation of tumor-suppressor genes as the characteristic abnormality in radio-induced cancer.

Squamous Cell Carcinoma of the Scalp After Radiotherapy for Tinea Capitis

BACKGROUND

Radiotherapy for tinea capitis was widely used in the 1930s and 1940s. There is a fourfold increase in the risk for developing nonmelanoma skin cancer in the scalp. Excision of lesions is challenging, as tissue around the wound is atrophic and susceptible to ischemia.

OBJECTIVE

To discuss the risk of skin cancer in the older patient who received scalp radiotherapy in childhood and options for scalp reconstruction after excision.

METHODS

A woman developed squamous cell carcinoma on the scalp 67 years after radiotherapy for tinea capitis.

RESULTS

The large excision defect was successfully grafted, avoiding the need for complex scalp reconstruction.

CONCLUSION

Patients who received scalp radiotherapy in childhood are at increased risk of developing nonmelanoma skin cancer. The unique anatomy of scalp tissue makes it difficult to close excisional defects. Skin grafting often fails, and complex flaps or the importation of vascularized tissue may be required.

A Reanalysis of Thyroid Neoplasms in the Israeli Tinea Capitis Study Accounting for Dose Uncertainties

In the 1940s and 1950s, children in Israel were treated for tinea capitis by irradiation to the scalp to induce epilation. Follow-up studies of these patients and of other radiation- exposed populations show an increased risk of malignant and benign thyroid tumors. Those analyses, however, assume that thyroid dose for individuals is estimated precisely without error. Failure to account for uncertainties in dosimetry may affect standard errors and bias dose-response estimates. For the Israeli tinea capitis study, we discuss sources of uncertainties and adjust dosimetry for uncertainties in the prediction of true dose from X-ray treatment parameters. We also account for missing ages at exposure for patients with multiple X-ray treatments, since only ages at first treatment are known, and for missing data on treatment center, which investigators use to define exposure. Our reanalysis of the dose response for thyroid cancer and benign thyroid tumors indicates that uncertainties in dosimetry have minimal effects on dose-response estimation and for inference on the modifying effects of age at first exposure, time since exposure, and other factors. Since the components of the dose uncertainties we describe are likely to be present in other epidemiological studies of patients treated with radiation, our analysis may provide a model for considering the potential role of these uncertainties.

Radiation-induced schwannomas of the nervous system. Report of five cases and review of the literature

Radiation therapy has important delayed effects on the central nervous system. Prominent among these effects is radiation necrosis of nervous tissue, but an oncogenic effect is also recognized. Both benign and malignant intracranial tumors can develop in irradiated fields, particularly in children. Most of these tumors are sarcomas, meningiomas or gliomas and only occasionally schwannomas. We report 5 cases of postirradiation acoustic nerve schwannoma observed in our Department.

Prolactinoma and other head and neck tumors after scalp irradiation

Tumors of the thyroid and parathyroid glands may develop together or separately in patients who previously have been exposed to head and neck irradiation. Whether cranial irradiation confers an increased risk for pituitary adenoma remains unknown. We report the case of a 52-year-old woman who was treated during childhood for tinea capitis with scalp irradiation and later in life developed a prolactin-secreting tumor, a parathyroid adenoma, a benign thyroid lesion, and a basal cell carcinoma of the skin. She was treated successfully with bromocriptine and surgical removal of the parathyroid adenoma. Molecular analysis of the parathyroid tissue failed to demonstrate any abnormality of the multiple endocrine neoplasia Type 1 gene. This case report is the first to describe a prolactin-secreting tumor that developed in association with other endocrine neoplasia after head and neck irradiation. Our case suggests that multiple endocrine neoplasia may develop in a sporadic pattern after scalp irradiation.

Radiation-induced meningioma: a descriptive study of 253 cases

OBJECT

Ionizing radiation is the only established risk factor recognized today in the causation of meningioma. The aim of the present report is to describe the demographic and clinical characteristics of a large series of 253 patients with radiation-induced meningiomas (RIMs). These parameters were compared with those of 41 patients with meningiomas in whom there was no previous history of irradiation (non-RIM group) and with other series of patients presented in the literature.

METHODS

The cases of RIM were recruited from a cohort of approximately 11,000 individuals who had been treated with ionizing radiation during childhood for tinea capitis and from a group of individuals who, as adults, applied for compensation because of that treatment. The non-RIM group was identified through the Israeli Cancer Registry. Exposure to radiation was carefully validated among all cases of RIM and absence of previous irradiation was verified for all patients in the non-RIM group. Significantly, a lower patient age at diagnosis, higher prevalence of calvarial tumors, higher proportion of multiple meningiomas, and a nonsignificant higher recurrence rate were observed among patients with RIM compared with the non-RIM group. The mean latency period from date of radiation exposure to development of a meningioma among the RIM group was approximately 36 years.

CONCLUSIONS

The findings of this study agree with those of other studies indicating the demographic, clinical, and even genetic variability between RIM and non-RIM cases. The existence of two different subtypes of meningiomas may have profound implications for screening, early diagnosis, and therapy of meningiomas.

A possible association between ionizing radiation and pituitary adenoma: a descriptive study

BACKGROUND

Despite the recognition of ionizing radiation as a causal risk factor for a variety of solid tumors (including brain tumors), to date, such an association with pituitary adenoma (PA) has not been demonstrated.

METHODS

To evaluate a possible association between past exposure to radiation and the occurrence of PA, the authors reviewed about 4900 medical records of patients who had been irradiated in childhood for tinea capitis. An additional search for patients was performed using the Israel Cancer Registry. The average radiation dose to the pituitary gland was estimated as 0.56 grays, and, for all patients, a meticulous validation of the irradiation was performed.

RESULTS

A group of 16 patients who developed symptomatic PA after childhood exposure to radiotherapy were identified. Overall, the clinical and demographic characteristics of these patients were similar to other series reported in the literature. There was an apparently high rate of second primary tumors (25%), all of them in the irradiated area, diagnosed among this group. The methodologic issues that limit the demonstration of a possible association between radiation and PA and the epidemiologic and experimental findings in the literature are discussed.

CONCLUSIONS

In view of the ample amount of evidence identifying low-dose ionizing radiation as a risk factor for a number of intracranial tumors as well as for tumors arising in endocrine organs, a radiation immunity of the pituitary gland is difficult to accept. Hence, the authors suggest that this series should be considered as preliminary observation that supports the role of ionizing radiation in the development of this tumor.

'Clicking-brain syndrome': a curious cause of insomnia

This case report describes a curious cause of insomnia. A 93-year-old woman presented to our follow-up clinic with the complaint of insomnia secondary to an audible click emanating from her skull. The site of loud biphasic-sound production corresponded to an area of the scalp where a squamous cell carcinoma had been removed 11 years previously.

Thyroid cancer following scalp irradiation: a reanalysis accounting for uncertainty in dosimetry

In the 1940s and 1950s, over 20,000 children in Israel were treated for tinea capitis (scalp ringworm) by irradiation to induce epilation. Follow-up studies showed that the radiation exposure was associated with the development of malignant thyroid neoplasms. Despite this clear evidence of an effect, the magnitude of the dose-response relationship is much less clear because of probable errors in individual estimates of dose to the thyroid gland. Such errors have the potential to bias dose-response estimation, a potential that was not widely appreciated at the time of the original analyses. We revisit this issue, describing in detail how errors in dosimetry might occur, and we develop a new dose-response model that takes the uncertainties of the dosimetry into account. Our model for the uncertainty in dosimetry is a complex and new variant of the classical multiplicative Berkson error model, having components of classical multiplicative measurement error as well as missing data. Analysis of the tinea capitis data suggests that measurement error in the dosimetry has only a negligible effect on dose-response estimation and inference as well as on the modifying effect of age at exposure.

Multiple basal cell carcinomas developed after radiation therapy for tinea capitis: a case report

Development of skin neoplasms is the most important complication of radiation therapy. There are contradictive reports about the type of these neoplasms. Squamous cell carcinomas are considered the most frequent tumors arising on chronic radiodermatitis areas, but recent studies have demonstrated that the type of neoplasm occurring in response to ionizing radiation exposure depends on several factors. Herein we report a patient who had received low-dose radiation for the treatment of tinea capitis and developed multiple basal cell carcinomas in the radiated areas after a long latent period of 53 years.

Cancer risk from low-level ionizing radiation: the role of age at exposure

This article examines methodological issues related to epidemiologic investigations of the influence of age at exposure on radiation risk estimates; the epidemiologic literature on the role of age at exposure in radiation-cancer associations; and biological mechanisms that may account for associations observed in these studies. There is substantial evidence that young children, and especially the fetus, are highly vulnerable to ionizing radiation. Investigations also suggest that sensitivity may increase at the oldest ages of exposure. Further attention to modifying factors in radiation-cancer associations, such as age at exposure, may help to protect workers and the public by improving our understanding of sensitivity variation within populations.

An iatrogenic epidemic of benign meningioma

Head irradiation, the acceptable mode of treatment for tinea capitis in the past, is recognized today as a causative factor for meningioma. This treatment was applied en mass to immigrants coming to Israel from North Africa and the Middle East during the 1950s. In order to estimate the effect of the differential radiation treatment on the rates of meningioma in the total population, the authors assessed time trends of this disease in Israel over the past 40 years by main ethnic origin. Cohort analysis shows a marked incidence rise in the North African-born cohorts born in 1940-1954 starting from the 1980s. A similar pattern is seen in the Middle Eastern born, although the increase is not as sharp. In consequence, there is a crossover of the interethnic incidence curves in the 1940-1949 cohort. Comparison of the relative risk between 1940-1954 cohorts that comprised most of the irradiated with 1930-1939 cohorts, who were largely free of the radiation, shows that the North African born have the largest relative risk of 4.62, followed by the Middle Eastern born, with a relative risk of 1.95, while the European-American born have a relative risk close to 1. The differences between the three areas of birth are statistically significant. The data illustrate the potential risk of administering highly potent therapy for an essentially benign disease that led, in turn, to a drastic change in the national meningioma pattern.

Multiple skull base meningioma: case report

BACKGROUND

The incidence of multiple skull base meningiomas varies from 1 to 3% in different series. Skull base meningiomas are rare. The pathogenetic role of low-dose radiation seems to be fairly well established in the oncogenesis of meningiomas. Calvarial location and multiplicity seem to be among the distinctive features of radiation-induced meningiomas. Skull base location is a very rare occurrence, mainly because the path of irradiation does not significantly involve this region.

CASE REPORT

We describe a rare case of simultaneous occurrence of two skull base meningiomas in a 66-year-old female. This patient underwent low-dose irradiation for tinea capitis when she was 8 years old. The patient complained of nuchal pain, paresthesias in both hands, and progressive weakness on her right side. She was admitted to the hospital in September 1994. An MRI showed two masses, one located at the level of the tuberculum sellae and the other at the foramen magnum. These seemed very likely to be multiple meningiomas. The latter lesion, which was more symptomatic and dangerous, was operated on first. Six months later, elective treatment of the suprasellar meningioma was performed with success.

CONCLUSION

The actual role of previous head irradiation in the oncogenesis of the present meningiomas remains somewhat unclear. Proper management and judicious use of skull base surgery techniques were key factors in the successful treatment of the patient.