Objectives: To assess the frequency and types of cancer found in children presenting to our Unit with musculoskeletal symptoms over a 10-year period.
Methods: The medical records of patients with musculoskeletal symptoms and a final diagnosis of cancer were reviewed. In each case age, gender, presenting symptoms, laboratory data, diagnostic procedures, provisional and final diagnoses, and time between clinical onset and correct diagnosis were reviewed.
Results: An underlying neoplasia was found in 10 of 1,254 patients (<1%) complaining of musculoskeletal symptoms. The types of malignancies found included acute lymphocytic leukemia (ALL) (6 cases), lymphoma (2 cases), neuroblastoma (1 case), and Ewing's sarcoma (1 case). The mean time between disease onset and final diagnosis was 3.2 months. The most common presenting feature was monoarthritis, involving the larger joints such as the elbows, knees or ankles. Juvenile idiopathic arthritis (JIA) was the most frequent provisional diagnosis. In the preliminary hematologic evaluation, eight patients had an increased erythrocyte sedimentation rate (ESR) or C-reactive protein (CRP) value. White blood cell (WBC) count was normal in almost all children, with a normal differential count. Lactic dehydrogenase (LDH) was raised in all children. Bone marrow aspirates and lymph node or bone biopsies were necessary to reach the final diagnosis.
Conclusions: A malignancy should always be excluded in children with musculoskeletal symptoms, especially when the clinical pattern is not characteristic of a specific rheumatic disease. Routine laboratory tests may be misleading. The simultaneous presence of high LDH or alpha-hydroxybutyric dehydrogenase (alpha-HBDH) levels and raised ESR or CRP, even with normal blood cell counts, should lead to additional investigations.
Relevance: All patients presenting with arthritis or other musculoskeletal symptoms should have a thorough clinical examination. Disproportionate pain levels and an atypical pattern of "arthritis," especially in the presence of systemic manifestations, suggest a possible underlying malignancy.