Bone marrow involvement is not manifest in the early stages of childhood acute lymphoblastic leukaemia

INTRODUCTION: Acute lymphoblastic leukaemia (ALL) in children may have atypical presentations causing diagnostic delay. Guidelines for prompt referral have been published. The utility of the specified criteria is unknown.MATERIAL AND METHODS: Symptoms, signs and laboratory findings at the time of diagnosis were reviewed in a consecutive series of 100 children with ALL in order to determine the frequency of atypical features and to evaluate the Danish referral guideline.RESULTS: Only 36% had involvement of all three haematopoietic cell lines, and 23% presented with the classic clinical triad of pallor, fever and purpura. Symptoms of bone marrow insufficiency had been present in 77% for an average of two weeks as a late occurrence following musculoskeletal pains (in 49%, duration eight weeks) and constitutional symptoms (in 82%, duration four weeks). Organ infiltration was manifest in 71%. In 22%, only one or no cell count was abnormal; in this group, musculoskeletal symptoms were more frequent and symptom duration longer (two months versus one month). In 15%, lymphoblasts could not be detected in the blood. At the time of diagnosis, the Danish criteria for accelerated investigation were fulfilled in 98% of cases.CONCLUSION: The clinical presentation of ALL is variable, and full-blown bone marrow insufficiency is a late occurrence as the disease progresses. Reduction of the diagnostic interval requires meticulous examination for organomegaly and attention to subtle haematologic changes.FUNDING: Not relevant.TRIAL REGISTRATION: Not relevant.