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

Radiation-Induced Primary Brain Lymphoma: A Case Report

A patient who developed primary brain lymphoma 6 years following whole brain irradiation due to a low-grade glioma is described. The patient had no evidence of congenital or acquired immunodeficiency state and achieved a good and prompt response to aggressive chemotherapy, including high-dose methotrexate. The previous radiation therapy is implicated in the etiology of the lymphoma because of the geometric coincidence, the relatively long latency period and the different histology. A brief review of current literature is reported.

Adenocarcinoma of the Lung in down Syndrome: First Clinical Report

Lung cancer is rare in persons with Down syndrome, and the clinical presentation of the disease has not been described in adults with intellectual disability. We report the first detailed clinical observation of a 33-year-old man with Down syndrome who developed an adenocarcinoma of the lung 30 years after an acute lymphoblastic leukemia in infancy. Despite advanced disease at initial presentation and extensive tumor spreading during the course of the disease, he presented with unusually mild symptoms. The scarcity of lung cancer in people with intellectual disability, and particularly those with Down syndrome, is due, in part, to reduced tobacco use. However, cytogenetic and molecular studies suggest that genes mapping to chromosome 21 may protect against lung cancer. Numerous reports also suggest that, in persons with Down syndrome and other intellectual disability, cancers are often discovered late, leading to loss of the chance of cure and recovery.

Diagnostic and therapeutic challenges owing to concurrent pontine glioma and acute lymphoblastic leukemia

The presence of 2 active primary tumors in a child is both unusual and challenging. This places the clinician and the family in a difficult situation while planning the treatment. The concurrent presence of a low-grade brain stem glioma and acute lymphoblastic leukemia in a genetically normal girl is presented. The problems encountered with diagnosis and treatment are discussed here.

A Low-Grade Follicular Thyroid Carcinoma in a Woman with down Syndrome

Aims

Analysis of a thyroid neoplasm in a person with Down syndrome.

Method

Report of a case and review of the literature.

Results

A 34-year-old woman with Down syndrome developed a right thyroid low-grade follicular carcinoma. She is alive 20 years after the discovery of the initial tumor. A review of the literature including epidemiological studies revealed only one unspecified cancer, one papillary carcinoma and one lymphoma. Persons with Down syndrome present an excess of goiter and thyroiditis and often are overweight and have low serum selenium, all these conditions being risk factors for thyroid carcinomas.

Conclusion

Thyroid malignant neoplasms are very rare in persons with Down syndrome. We suspect that some constitutional, hormonal and genetic factors could protect these subjects against thyroid carcinoma.

Pattern of malignant disorders in individuals with Down's syndrome

The pattern of occurrence of malignant disorders in people with Down's syndrome (DS) is unique and may serve as a model in the search for leukaemogenic genes and tumour suppressor genes on chromosome 21, since the risk of leukaemia is higher in individuals with DS than in non-DS individuals. Acute lymphoblastic leukaemia in DS shares many of the clinical characteristics of the same malignancy in other patients, and with current intensive therapy the long-term survival is similar. Myelodysplastic syndrome and acute myeloid leukaemia have unique clinical characteristics in these patients and are best described as a single disorder, termed myeloid leukaemia of DS. When these patients are treated intensively, they show better survival rates than patients without DS. This may be related to increased expression of genes on chromosome 21 contributing to increased chemosensitivity. Chronic myeloid leukaemia and chronic lymphocytic leukaemia occur less often than expected. With the exception of an increased risk of retinoblastoma, germ-cell tumours, and perhaps lymphomas, the risk of developing solid tumours is lower in both children and adults. Breast cancer is almost absent, and the risk of a second malignant disease after treatment for leukaemia also appears to be decreased. Increased susceptibility to apoptosis in DS may result in cell death rather than malignant transformation after major cell injuries. This hypothesis would explain the decreased risk of both solid tumours and secondary cancers.

Brainstem tolerance to conformal radiotherapy of skull base tumors

PURPOSE

The aim of this study was to analyze the long-term incidence of brainstem toxicity in patients treated for skull base tumors with high dose conformal radiotherapy.

METHODS AND MATERIALS

Between 1974 and 1995, 367 patients with chordomas (n = 195) and chondrosarcomas (n = 172) of the base of skull have been treated with combined megavoltage photon and 160 MeV proton radiotherapy. Following 3D treatment planning with delineation of target volumes and critical nontarget structures dose distributions and dose-volume histograms were calculated. Radiotherapy was given an 1.8 Gy or CGE (=Cobalt Gray Equivalent) dose per fraction, with prescribed target doses ranging from 63 CGE to 79.2 CGE (mean = 67.8 CGE). Doses to the brainstem surface were limited to < or = 64 CGE and to the brainstem center to < or = 53 CGE.

RESULTS

Follow-up time ranged from 6 months to 21.4 years (mean = 42.5 months). Brainstem toxicity was observed in 17 of 367 patients attributable to treatment, resulting in death of three patients. Actuarial rates of 5 and 10-year high-grade toxicity-free survival were 94 and 88%, respectively. Increased risk of brainstem toxicity was significantly associated with maximum dose to brainstem, volume of brainstem receiving > or = 50 CGE, > or = 55 CGE, and > or = 60 CGE, number of surgical procedures, and prevalence of diabetes or high blood pressure. Multivariate analysis identified three independent factors as important prognosticators: number of surgical procedures (p < 0.001), volume of the brainstem receiving 60 CGE (p < 0.001), and prevalence of diabetes (p < 0.01).

CONCLUSIONS

Tolerance of brainstem to fractionated radiotherapy appears to be a steep function of tissue volume included in high dose regions rather than the maximum dose of brainstem alone. In addition, presence of predisposing factors as well as extent of surgical manipulation can significantly lower brainstem tolerance in the individual patient.

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.

Intracranial germinoma with Down's syndrome: a case report and review of the literature

BACKGROUND

Down's syndrome's association with malignancies such as leukemia is well known, but its association with brain tumor appears to be rare. We reviewed such rare cases of Down's syndrome and intracranial germ-cell tumor.

CASE REPORT

A 10-year-old boy with Down's syndrome and intracranial germinoma located in the left basal ganglia is reported. The patient presented with right hemiparesis and was treated with a combination of surgery, chemotherapy with cisplatin and etoposide, and irradiation.

CONCLUSIONS

We speculate that the percentage of germ-cell tumors is high among Down syndrome patients with brain tumors and that the most common site is the basal ganglia.

Aspects of the neoplasms observed in patients with constitutional autosomal trisomy

A review of the literature reveals numerous clinical case reports, systematic histologic analyses, epidemiologic studies, and large series of tumors showing that subjects with trisomy 8, 9, 13, 18, and 21 have an excess of hematologic and various solid tumors compared to the general population. These tumors more frequently affect particular organs for a given type of trisomy. A large proportion of tumors are observed during fetal and neonatal life, are incompletely developed, and subsequently regress. In older children or even adults, tumors are less frequent, are often found on the same organs as earlier in life, are more aggressive, and do not involute. The mechanism responsible for the development of these neoplasms could be similar to that which generates the malformations in these children and may result from cooperation of the chromosomal abnormality with physiologic growth phenomena, which are particularly active early in life. Trisomic subjects must be carefully followed in order to detect tumors as early as possible and to allow treatment under optimal conditions.