GOUT IN CHILDHOOD LEUKEMIA. REPORT OF A CASE AND CONCEPTS OF ETIOLOGY

A multicenter case-control study on predictive factors distinguishing childhood leukemia from juvenile rheumatoid arthritis

OBJECTIVE

Acute lymphocytic leukemia (ALL) often presents with musculoskeletal concerns such as pain or swelling, even before appearance of blasts in the peripheral blood. Such presentation may lead to misdiagnosis of a child with juvenile rheumatoid arthritis (JRA). This study was designed to identify the predictive factors for leukemia using basic clinical and laboratory information.

METHODS

A retrospective chart review was performed using a simple questionnaire to compare the clinical and laboratory findings present during the initial visit to a pediatric rheumatology clinic for 277 children who were ultimately diagnosed with either JRA (n = 206) or ALL (n = 71). Sensitivity and specificity analysis of a variety of parameters, both singly and in combination, was performed to identify predictive value for ALL.

RESULTS

The majority (75%) of children with ALL did not have blasts in the peripheral blood at the time of evaluation by pediatric rheumatologists. In children presenting with unexplained musculoskeletal complaints, the 3 most important factors that predicted a diagnosis of ALL were low white blood cell count (< 4 x 10(9)/L), low-normal platelet count (150-250 x 10(9)/L), and history of nighttime pain. In the presence of all 3, the sensitivity and specificity for a diagnosis of ALL were 100% and 85%, respectively. Other findings, including antinuclear antibody, rash, and objective signs of arthritis, were not helpful in differentiating between these diagnoses because they occurred at similar rates in both groups.

CONCLUSIONS

When a child develops new-onset bone-joint complaints, the presence of subtle complete blood count changes combined with nighttime pain should lead to consideration of leukemia as the underlying cause.

Rheumatological manifestations of the leukaemias and graft versus host disease

Bone and joint involvement in the leukaemias is discussed. Particular emphasis is placed upon osteoarticular presentations which may predate the haematological changes or divert attention from the primary pathology. A description of acute and chronic graft versus host disease is presented with particular emphasis on the rheumatological manifestations.

Renal dysfunction and hyperuricemia at presentation and relapse of acute lymphoblastic leukemia

Hyperuricemia is an unusual presenting feature of acute lymphoblastic leukemia (ALL) and is generally associated with a large leukemic cell burden. We describe three children with T-cell ALL who presented with acute renal failure and very high serum uric acid concentrations, despite a relatively small leukemic cell burden. Two of the three patients had normal complete blood counts without circulating blasts or other physical evidence of leukemia. An isolated renal relapse in one case was associated with hyperuricemia, increased renal excretion of uric acid, and renal dysfunction. An unusually high rate of purine catabolism of the lymphoblasts may cause hyperuricemia in these cases. Unexplained hyperuricemia should prompt a search for occult malignancy.

Acute renal failure and gout as presenting features of acute lymphoblastic leukaemia

A leukaemic child is described who presented with renal failure and gout attributable to hyperuricaemia before the leukaemia could be diagnosed.