Vertebral collapse in childhood leukemia.

Leukemia is the most common form of cancer in children. At the time of initial presentation, 10% of children have normal peripheral blood counts. Appendicular skeletal involvement occurs in approximately 50% of cases. The literature does not clearly define the incidence of spinal involvement, with only a total of 31 cases located in a review of the literature. If case reports are excluded and series that reported the frequency of spinal involvement are summarized, only 16 of 615 cases had spinal involvement. In only one of 31 was it clear that the patient had a normal peripheral blood count at the time of diagnosis. This article adds to the literature two patients who had normal peripheral blood counts and spinal involvement with acute lymphocytic leukemia. Patients with leukemia may have significant symptoms and radiographic signs with normal peripheral cell blood counts at the time of initial presentation.