chronic lymphocytic leukaemia symptomsacute lymphocytic leukaemialeukaemia cancer symptomslymphoblastic leukaemia symptomschronic leukaemia symptomssymptoms of leukaemia in teenagerleukaemia relapse symptomsleukaemia nosebleedssymptoms of leukaemia in elderlyleukaemia petechiaeacute leukaemia symptomslymphocytic leukemia treatment