[Malignant disease presenting as rheumatic manifestations]

Musculoskeletal pain is a frequent complaint in pediatrics in both tertiary and primary care. Although musculoskeletal symptoms are not usually related to severe disease, they can represent the first manifestation of an occult malignancy.

To describe the clinical manifestations and complementary findings of the patients referred to a pediatric rheumatology unit with a final diagnosis of malignancy.

We performed a retrospective review of all the children referred to a pediatric rheumatology unit between 1992 and 2002 whose final diagnosis was cancer.

Of 3,982 patients referred, 10 had a final diagnosis of neoplasia (0.25 %). Six children were diagnosed with acute lymphoblastic leukemia, two with Langerhans' cell histiocytosis, one with Ewing's sarcoma, and one with metastases from retinoblastoma. The most frequent symptoms were arthralgias, limp, or back pain. Laboratory studies revealed anemia and a significant increase in sedimentation rate and lactate dehydrogenase values. Imaging studies contributed significantly to the diagnosis. The diagnosis was confirmed by bone marrow aspirate in children with leukemia and by bone biopsy in those with bone tumors.

Malignancies should be considered in the differential diagnosis of children with musculoskeletal pain, especially in the presence of organomegalies or abnormal laboratory or imaging studies.