background : primary central nervous system involvement and central nervous system relapse are poor prognostic events in acute lymphoblastic leukemia. due to severe skeletal and endocrine complications of craniospinal radiotherapy, only cranial radiotherapy is advisable. however only 15% of the cases with central nervous system relapse may remain in remission; a second central nervous system or...

The aim of this article is to draw attention towards various natural but unanswered questions related the lower central series unit group an integral ring.