Malignant glioma as a secondary malignant neoplasm after radiation therapyfor craniopharyngioma - Report of a case and review of reported cases

Background: The development of a secondary neoplasm in childhood cancer sur vivors attains growing importance due to the reported excellent survival an d therefore the long exposure to potentially carcinogenic effects of treatm ent. Case Report: We report a 14-year-old girl in whom a large craniopharyn gioma (CP) was diagnosed. After surgery, radiation therapy (RT) was given f or residual tumour. Discrete progression necessitated further surgery, resu lting in permanent tumour control. Soon after the second surgery hypothalam ic-pituitary dysfunction developed together with obesity. Supportive hormon e therapy was initiated. Growth hormone (GH) therapy was also given for 15 months. Four years after the diagnosis, a cerebropontine anaplastic astrocy toma WHO grade III was detected, with the main lesion being at the dorsal e dge of the irradiated area. The girl died 1 month later from this secondary presumably radiation-induced tumour. Only recently a second child with RT for a CP was diagnosed with malignant glioma in our hospital. Case Reports in the Literature: 12 other cases of malignant glioma have been reported af ter RT for CP. Including our present cases, the mean latency period was 10. 7 years (median 9.6 years). However, the shortest latency periods were foun d in patients who had received GH therapy. In numerous cases, the secondary tumour was seen at the edge of the irradiated volume, and not in the regio n with the highest absorbed dose. Conclusions:Therapy-induced secondary gli omas after treatment of CP or other intracranial tumours are rare but drama tic late events with a very poor prognosis. Including our own 2 patients, w e reviewed 14 cases of CP with occurrence of a secondary, probably radiatio n-induced malignant glioma. The short latency periods for patients treated with GH is remarkable. We therefore suspect that GH therapy may accelerate the development of a secondary brain tumour. We are reluctant to recommend GH therapy in conventionally irradiated CP patients. In order to seriously answer the questions about therapy-induced secondary neoplasms, a lifelong follow-up is mandatory for all patients who are survivors of childhood canc er.