Histologic analysis of brains from xenografted mice. (A) Line drawing of a coronal section of murine brain showing approximate locations (zones i-iv) of images shown in panels B-D. (B) Photomicrographs of hematoxylin and eosin (H&E)-stained brain sections. Top: low-power view of cerebral cortex and leptomeninges (original magnification ×5); bottom: close-up of a central meningeal vessel (original magnification ×40). Long thin arrow indicates leukemic cells in the vessel wall. Bar represents 100 μm. (C) H&E (top) and corresponding anti-human CD45 (bottom) staining of leukemic deposits. Left: Cells surrounding the dural venous sinus (original magnification ×20); center: cells within choroid plexus (original magnification ×20); right: high-power view of meninges (original magnification ×40). Bar represents 100 μm. (D) Postmortem image of grade 2 arachnoid leukemia (zone ii) in a child with ALL (H&E, original magnification ×33), reproduced with permission from Price and Johnson.4 (E) Representative coronal sections (all zone iv) from mice engrafted with a CNS-3 sample and 5 matched CNS-1 controls (H&E, original magnification ×40). Bar represents 50 μm. Thick arrows (panels B-E) mark the leukemic infiltrate within the leptomeninges and asterisks (panels B and E) mark leukemic infiltrates within the calvarial BM cavity. Numbers preceded by the # symbol (panels B, C, and E) denote the sample identifiers in Table 1.
