BACKGROUND: Acute lymphoblastic leukemia (ALL) is the most common childhood 
malignancy. Although it was considered to be a poor prognostic disease, modern 
treatment protocols (aggressive chemotherapy and prophylactic cranial 
irradiation) have resulted in dramatically improved survival rates. In a group 
of low-risk ALL patients, the 5-year survival rate is estimated to be 85%. 
However, ALL patients who undergo this treatment are at risk of developing 
secondary neoplasms related to treatment, which has become an increasingly 
recognized problem.
CASE DESCRIPTION: A 3-year-old boy with ALL was successfully treated with 
chemotherapy (vincristine, prednisolone, mercaptopurine and methotrexate) and 
prophylactic cranial irradiation (total 18 Gy). At the age of 23, he was 
admitted to our hospital for weakness in the right leg. Computed tomography and 
magnetic resonance imaging revealed a parasagittal tumor of the left 
frontoparietal lobe with perifocal edema. The tumor was completely removed 
surgically and pathohistologically diagnosed as atypical meningioma.
CONCLUSION: Long-term survivors who received radiotherapy for ALL in childhood 
are at risk for late complications, including radiation-induced meningioma. 
Therefore, careful follow-up neurological examinations, for example magnetic 
resonance imaging, are indicated in these patients. In addition, late 
complications should be taken into account during the initial planning of 
prophylactic radiotheraphy dosage, which has implications for informed consent 
of the patient.