RESUMEN
Lymphoma is a common cancer of childhood. Its pathologic subtype of anaplastic large cell Non-Hodgkins Lymphoma (NHL) is rare and spread to the central nervous system (CNS) is even rarer. We present here such a case who presented to us with an acute history of fever and diplopia and co-existent polyarthritis since 8 years diagnosed as NHL with CNS involvement. CNS involvement is a rare presenting manifestation of NHL and is an important cause of morbidity and mortality in these patients. Chronic arthritis could be a risk factor or manifestation of immunodeficiency or immune dysregulation when associated with lymphoma. It is important to suspect NHL in children presenting with these symptoms for prompt evaluation and better clinical outcome.