Clinical History:

This patient was undergoing chemotherapy for leukemia and developed severe pulmonary disease with multiple large areas of consolidation.  Bacterial cultures were negative.  At autopsy the lung had the appearance illustrated in Figure 1.  Figure 2 shows the histology of the structure at the arrow in Figure 1.  Figure 3 shows histological appearance of the pulmonary parenchyma.

Questions:

1.  The lung shown in Figure 1 is heavy and has a nodular cut surface and a shaggy pleural surface.  The histology shown in Figure 1 reveals a microorganism -  is this a typical pathogen of otherwise healthy individuals?

2.  The arrow in Figure 1 points at a vascular structure containing a reddish-tan, irregular mass.  (Fill in the blank) - This is a ______________in a major branch of the pulmonary artery.

3.  What could lead to this lesion in the pulmonary artery? Think both about this patient and other patients such as in Case 1.  Figure 2 shows histology of the artery wall in this case.

4.  (Fill in the blank) - Some of the damage to lung tissue in this case is probably due to _____________________  as well as to infection.  Why might pulmonary artery occlusion not lead to overt damage in many cases?  How do such lesions resolve?

5.  What is the likely reason for her death from what we know?