Splenic disruption by megakaryoblastic proliferative disorder. After treatment for 9 days with 5 mg/kg per day of intraperitoneal flavopiridol, mice were killed for histologic analysis of spleens. Comparisons include C57BL/6 (Wt) and GATA-1Lo (G1Lo) strains treated either with saline or flavopiridol (FP). Shown are representative hematoxylin and eosin–stained splenic sections (original magnification ×100).