Vertebral collapse and normal peripheral blood cell count at the onset of acute lymphatic leukemia in childhood.

Acute lymphatic leukemia presenting with bone pain and spine involvement is a recognized clinicopathologic complex that can mimic a wide range of orthopaedic conditions. Bone pain as the presenting complaint is common, with a reported incidence of 27% to 50%. Radiologic abnormalities associated with leukemia in children has been described previously. In the literature, the incidence of spinal involvement is controversial, but there is agreement that the spine is less commonly involved than are the long bones. At the onset of the disease, only 10% of children have normal peripheral blood counts. If the patient has spinal involvement and a normal leukocyte count, the diagnosis is often unclear. Only three of these patients have been described in the literature; this article adds one more patient with acute lymphatic leukemia with back pain as the main symptom, vertebral collapse, and a normal peripheral blood cell count at the time of initial presentation. It illustrates that delay in diagnosis frequently occurs, with the classic features of the disease being uniformly absent.