The coincidence of multiple sclerosis (MS) and glioblastoma has been reported in 
several anecdotal reports. Little is known concerning the effects of radio- 
and/or chemotherapy on demyelinating brain lesions in MS patients. Moreover, 
there are no data concerning the effect of concomitant radiochemotherapy 
according to the STUPP protocol on the course ofMS in patients with coexisting 
glioblastoma. A 43-year-old male patient was diagnosed for relapsing-remitting 
MS in 1997. He received interferon and glatiramer acetate for immunomodulatory 
treatment and was stable until 2006 (EDSS < 1.5), when neurological 
deterioration occurred. He developed a left-sided hemiparesis, and an MRI showed 
right temporal contrast-enhancing mass lesion. A subsequent tumor resection was 
performed and histology revealed a glioblastoma. At the beginning of 
radiochemotherapy, treatment for multiple sclerosis (glatiramer acetate) was 
stopped. The tumor responded well to treatment and was clinically as well as 
radiologically stable until 9 months after diagnosis of glioblastoma. The 
typical radiological MS lesions remained unchanged. The patient died 12 months 
after diagnosis of glioblastoma due to tumor progression. This report 
demonstrates that concomitant radiochemotherapy according to the STUPP protocol, 
was safe in our patient with respect to the radiological as well as the clinical 
course of multiple sclerosis.