What are the musculoskeletal features of leukemia and lymphoma?
Leukemia can present as a symmetric, asymmetric, or migratory polyarthritis or as bone pain. It can be the presenting manifestation in up to 6% of patients with childhood leukemia. Articular manifestations in acute leukemia occur in approximately 14% to 50% of children (acute lymphoblastic leukemia most common) and 4% to 16% of adults. Joint pain typically involves the ankle, shoulder, or knee and has been attributed to leukemic synovial infiltration. Bone pain due to subperiosteal infiltration occurs in up to 50% of patients. Long bone pain is more common in children, whereas back pain is more common in adults. The joint and bone pain may be out of proportion to the clinical findings and may be nocturnal. Children may be initially diagnosed with juvenile idiopathic arthritis given the severity of the arthritic symptoms. Synovial effusions are uncommon, mildly inflammatory, and leukemic cells are rare. Hemorrhage into the joint can occur. The white blood cell count may be normal, but lactate dehydrogenase (LDH) levels are always elevated. Plain radiographs are normal in 50% at the onset of the bone pain but bone scintigraphy will detect involvement early. Metaphyseal rarefaction and osteolytic lesions are characteristic radiographic findings. The diagnosis is confirmed by bone marrow and/or synovial biopsy. The joint or bone pain is optimally treated with systemic chemotherapy.
Up to 25% of patients with non-Hodgkins lymphoma can have musculoskeletal symptoms, with bone pain being the most common. Lymphomatous arthritis is rare but should be suspected in patients with constitutional symptoms out of proportion to the severity of the arthritis. The diagnosis is confirmed by bone or synovial biopsy. Angioimmunoblastic T-cell lymphoma can be mistaken for an autoimmune disease. It typically presents with constitutional symptoms, fever, rash (maculopapular or urticarial), lymphadenopathy, and hepatosplenomegaly. Arthritis, vasculitis, Coombs-positive hemolytic anemia, and polyclonal gammopathy can also occur. Lymph node biopsy confirms the diagnosis. Prognosis is poor.
Notably, both leukemia and lymphoma patients can develop secondary gout especially on initiation of chemotherapy. Septic arthritis can also occur. Consequently, all acute arthritic attacks should have the joint aspirated and the synovial fluid sent for cell count, crystals, Gram stain, and culture.
