Bone Marrow Biopsy results in patients with ALL and controls.

Mean values and 95% confidence intervals. Bony trabecular surface area is given as a percentage of trephine biopsy specimen surface area.
* Percentage of crossing points occupied by element.
** Megakaryocytes were counted inside 20 whole squares of 0.02 mm2 each.
*** Osteoblasts were counted in 10 whole squares of 0.02 mm2 each.
**** Counted along all trabecular perimeters of the whole trephine biopsy specimen area.
# Geometric means (see Statistical Methods).
P values have not been corrected for multiple observations.
The surface areas of trephine biopsies were similar in the two groups. The proportion of the trephine biopsy occupied by bony trabeculae as traced by an electronic pen was slightly lower in patients with ALL than controls. However, there was no difference between the two groups in the crossing points occupied by bony trabeculae or the width of these trabeculae as measured under the grids. Sinusoids were detected less frequently in some ALLs but the width of sinusoids was the same in both groups. There was more extracellular matrix in the leukemia samples (P<0.0003) and a significantly higher number of reticulin fibres (P<0.0001).
Bone Marrow Biopsy results in patients with ALL and controls.