Figure 1.

Bone marrow findings and FoxO3 expression in a Ph+ALL patient at diagnosis and after treatment with bortezomib. (A) H&E stained slide of a bone marrow trephine core biopsy at diagnosis revealed marrow space occupied by immature precursor B-lymphoblasts. Blasts (indicated by arrows; ∼90% of marrow cellularity) have an open chromatin, sparse cytoplasm and high N:C ratio. Rare scattered hematopoietic elements were present (x1,000). (B) FoxO3 immunostains (1:100; Millipore, Billerica, MA) revealed that most of these immature blasts lacked FoxO3 (magnification x1,000). (C) H&E slide of bone marrow core biopsy after treatment with bortezomib. The marrow was hypocellular for age (∼10% cellularity). It revealed only rare blasts along with normal hematopoietic elements (x100). (D) FoxO3 stains revealed that FoxO3 expression was seen in small clusters of cells within the interstitium (arrows; x100), including precursor cells localized to the endosteal niche (inset; x1,000). Reticle bar represents 100 µ.