PMC5490243_01
(A) Chest Computed Tomography (CT) Scan Showing Left Lower Lobe Mass-Like Consolidation With Tumoral Components (Black Arrows) and Atelectasis at Diagnosis. A Small Adjacent Effusion (Star) and Numerous Punctuate Nodules Scattered Throughout the Lungs Are Present. (B) Chest CT Scan After 5 Months of Treatment With Erlotinib Showing Improvement in the Tumor Mass, Resolution of the Punctuate Nodules, and an Unchanged Pleural Effusion (Star). Drug-Induced Pneumonitis With Bilateral Areas of Confluent and Ground Glass Opacity (White Arrows) Has Developed. (C) Chest CT Scan 2 Months After Patient Discontinued Erlotinib and Started Prednisone Showing Improvement in Pneumonitis, With Residual Left Basilar Confluent Opacity (White Arrow) and Unchanged Mass-Like Consolidation (Black Arrow) and Decreased Pleural Effusion (Star). (D) Chest CT Scan 4 Months After Patient Stopped Erlotinib Showing Worsening of Tumor Burden, With Increased Left Lower Lobe Mass-Like Consolidation (Short Black Arrow), Numerous New Small Pulmonary Nodules (Long Black Arrows), and an Unchanged Small Pleural Effusion (Star). (E) Chest CT Scan 1 Month After the Start of Afatinib Showing Improvement in Tumor Burden, With a Decreased Left Lower Lobe Mass-Like Opacity and Resolved Pulmonary Nodules. No Pneumonitis Had Development. The Small Pleural Effusion (Star) Was Unchanged
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F1
A 61-year-old woman who had never smoked was diagnosed with stage IV EGFR-mutant lung adenocarcinoma that was metastatic to the lymph nodes, contralateral lung, and pleura (Figure 1A). Repeat computed tomography (CT) of her chest revealed her disease to be decreased but new patchy ground glass opacities were present throughout the right lung and left upper lobe (Figure 1B). She experienced an initial improvement in her clinical symptoms and on her CT scan (Figure 1C). A repeat CT scan, approximately 1 year after the diagnosis, demonstrated worsening left lower lobe opacities and bilateral enlarging pulmonary nodules, consistent with disease progression (Figure 1D). A repeat CT scan after 4 weeks showed a disease response to the treatment, with no recurrence of the inflammatory infiltrates (Figure 1E).
(Left) Hematoxylin and Eosin Sections at Medium Magnification Showing Alveolar Parenchyma With Chronic Interstitial Pneumonitis, Organizing Pneumonia (Black Arrows), and Focal Reactive Pneumocyte Hyperplasia (White Arrow). (Right) Hematoxylin and Eosin Sections at Higher Magnification Showing the Presence of Focal Non-Necrotizing Granulomas (Black Arrow)
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F2
She underwent bronchoscopy, and pathologic examination indicated an organizing pneumonia with focal non-necrotizing granulomas and chronic interstitial pneumonitis (Figure 2).