Summary

We report a case of multifocal demyelination within the central nervous system in a patient being treated for a left hemispheric gemnistocytic astrocytoma with radiation therapy and chemotherapy, comprising temozolomide (360 mg/day—days 1–5 every 28 days) and 13-cis-retinoic acid (100 mg/m²/day—separated into two doses administered every 12 h on days 1 through 21 every 28 days). Five months into her first round of chemotherapy, brain magnetic resonance imaging (MRI) demonstrated multifocal regions of T2 prolongation with associated gadolinium enhancement within the right cerebral hemisphere. Spectroscopic data were consistent with demyelination rather than neoplasia. Despite the incidentally identified radiological progression, new neurological symptoms were not described. Interval resolution of the demyelinating lesions was observed in the years following the discontinuance of her chemotherapy regimen with reactivation of the previously observed lesions and the development of new T2 foci 6 months into her second round of re-treatment for tumour progression 5 years later.