Correct!
1. Review the VATS lung biopsy
The patient’s course, CT scan, and response to corticosteroids are not very compatible with his diagnosis of chronic eosinophilic pneumonia. The VATS biopsy was obtained (Figure 3).
Figure 3. Progressively higher power views of the patient’s VATS lung biopsy.
The biopsy showed predominantly airspace disease, which was relatively homogeneous at low power (Figure 3A). Alveoli were filled with macrophages (Figure 3B) which had slightly granular cytoplasm. Occasional giant cells (Figure 3C) were present as were foci containing moderate numbers of eosinophils (Figure 3D). The biopsy lacked airspace edema, fibrin or significant acute lung injury as would be more typical of chronic eosinophilic pneumonia. These findings were thought to be most consistent with desquamative interstitial pneumonitis (DIP) rather than chronic eosinophilic pneumonia (3). There was no significant fibrosis histologically.
Chronic eosinophilic pneumonia is characterized histologically by the presence of a diffuse infiltrate of eosinophils within the alveolar spaces and the interstitium, typically associated with airspace edema, fibrin (Figure 4A) and in about 50% of cases, prominent foci of organizing pneumonia. The eosinophils are typically admixed with variable numbers of macrophages, from few to many (Figure 4B), and a mixed interstitial infiltrate of lymphocytes and plasma cells (Figure 4) (4). Variable findings include the presence of eosinophils within vascular walls (Figure 4C), eosinophilic microabscesses (Figure 4D), rare scattered multinucleated giant cells or granulomas, and scattered neutrophils.
Figure 4. Lung biopsy typical of chronic eosinophilic pneumonia.
DIP usually presents in the fourth-fifth decade with symptoms of dyspnea and cough and restrictive findings on pulmonary function testing. Furthermore, BAL findings in DIP often contain high numbers of eosinophils (3,5). Based on the clinical findings and the biopsy, both the clinician and the pathologist favored a diagnosis of DIP.
Which of the following has/have been reported to be beneficial for corticosteroid resistant DIP?