Figure 1

Evaluation of a boy with abdominal pain, night sweats, increased fatigue, petechiae, and a white blood cell count of 113 × 10³ /μL. A. Bone marrow core biopsy (100×) showed diffuse replacement of normal marrow elements by uniform sheets of round to oval lymphoblasts with indented to convoluted nuclei. B. Touch preparation of core biopsy material showed lymphoblasts with high nuclear to cytoplasmic (N:C) ratio, finely dispersed nuclear chromatin, and prominent nucleoli. C-D. Peripheral blood smear (100×) showed lymphoblasts with high N:C ratio and cytoplasmic pseudopods.