An enlarged liver and spleen and swollen lymph nodes are telltale signs that can help physicians distinguish acute lymphoblastic leukemia (ALL) from juvenile idiopathic arthritis (JIA) in children with a persistent history of bone and joint pain, a study has found.
The study, “Persistent osteoarticular pain in children: early clinical and laboratory findings suggestive of acute lymphoblastic leukemia (a multicenter case-control study of 147 patients),” was published in the journal Pediatric Rheumatology.
ALL is the most common form of cancer in children, accounting for approximately 25% of all diagnosed cases. In 15–30% of children, ALL is diagnosed based on a history of isolated, but persistent, episodes of joint and bone pain that are not associated with blood abnormalities.
However, research has shown that most children with histories of bone and joint pain are initially diagnosed with JIA, the most common rheumatic disease in pediatric patients.
Chronic joint pain, fever, anemia, lymphadenopathy (swollen lymph nodes), and an enlarged liver and spleen, or hepatosplenomegaly, can be found in both ALL and JIA.
A bone marrow examination is generally the best way to distinguish ALL from JIA. However, in cases without hepatosplenomegaly or lymph node swelling, and when complaints of joint and bone pain are restricted to one part of the body, differentiating between ALL and non-systemic forms of JIA may be more challenging.
Investigators from Centre Hospitalier Universitgaire Angers in France and their colleagues aimed to identify early clinical and laboratory findings that could help physicians distinguish ALL from JIA in children with persistent joint and bone pain.
They reviewed the medical records of children followed at four French university hospitals between 2000 and 2011. All had joint and bone pain lasting at least a month and were diagnosed with either ALL or JIA.
Each child with ALL was paired with two children of approximately the same age with JIA. Statistical analyses were used to compare clinical and laboratory data between the two groups.
The study included data from 49 children (median age of 7.3 years) diagnosed with ALL following a bone marrow examination, and 98 children (median age 7.6) diagnosed with JIA.
Lymph node swelling and liver and spleen enlargement were the clinical signs with the greatest differences between the two groups of children. Some 37 of the 49 children diagnosed with ALL had at least one of these signs, compared with just two of the 98 children with JIA.
In the children whose signs were either missed or disregarded, statistical analyses showed that the presence of non-articular bone pain (pain involving bones and muscles, but not joints), weight loss, fatigue, low white blood cell counts, and low platelet levels were all associated with ALL.
When seen together, these signs “should prompt a bone marrow examination in the presence of fever or elevated inflammatory markers,” the researchers said.
“Based on our findings, we propose a preliminary decision tree that could be tested in prospective studies,” they said.
A child with persistent joint or bone pain not associated with blood abnormalities should have a bone marrow examination to assess the presence of ALL, if he or she has an enlarged liver and spleen and swollen lymph nodes, the researchers said.
Even without those signs, bone marrow analysis should still be performed in children with symptoms that include fever, non-articular bone pain, weight loss, fatigue, and low white blood cell and platelet levels, they said.