Figure 12a. Pneumonia in a 46-year-old woman with breast cancer who had undergone high-dose chemotherapy and autologous bone marrow transplantation. (a) Chest radiograph shows ill-defined consolidation in the right cardiophrenic angle. (b) CT scan shows a triangular enhancing consolidation with round, well-defined, low-attenuation necrosis in the right middle lobe, findings that suggest pneumonia with abscess formation. The white blood cell count was 1200/mm3. The causative organism was not identified. (c) Radiograph obtained after empirical treatment with antibiotics shows complete resolution of the pneumonia.