1. What are the abnormalities?
2. What is the distribution?
Section 1
Look at images 1 and 2.
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1. What are the abnormalities? 2. What is the distribution?
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Image 2--End inspiration
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Section 2
Images 2 and 3 were obtained at different phases of breathing. These images demonstrate the HRCT differences between deep inspiration (image 2) and end-expiration (image 3).
Image 3--End-expiration
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Compare images 2 and 3. What are the differences in the normal lung and in the abnormal lung? | ||||||||||
Section 3
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Histologic Features Alveolar walls are slightly thickened, and type II cells are prominent. Many alveoli are filled with red cells and macrophages. Stains for hemosiderin were positive indicating that the blood was not a result of the biopsy. | ||||||
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Frequent Associated Finding Many patients with this entity have the changes shown here. These changes are focal and must be looked for carefully. Aside from the alveolar wall thickening, type II cell hyperplasia, and alveolar blood, PMNs are clustered in capillaries. Sometimes capillary wall necrosis (not shown here) can be seen. Find 2 clusters of PMNs in capillary walls. What is the diagnosis of the lesion? Find 2 foci of type II cells. | ||||||
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One cause of this lesion is characterized by linear deposits of immunoglobulin along alveolar walls as shown here. Find a distinct linear deposit. What is the specific disease? | ||||||
Differential diagnosis of large, symmetric regions of ground-glass opacity on HRCT: Pulmonary edema, pulmonary hemorrhage, acute interstitial pneumonia, acute respiratory distress syndrome, uremic lung, hypersensitivity pneumonia, atypical pneumonia (viral, pneumocystis, mycoplasmal), alveolar proteinosis, acute and chronic eosinophilic pneumonia, non-specific interstitial pneumonia, desquamative interstitial pneumonia, Churg-Strauss syndrome, and bronchioloalveolar carcinoma (rare).
Histologic differential diagnosis: (With capillaritis) Goodpasture's syndrome, collagen vascular disease (especially lupus erythematosus), Wegener's granulomatosis, microscopic polyangiitis, antiphospholipid syndrome, IgA nephropathy, idiopathic pulmonary hemosiderosis; (without capillaritis) coagulopathies, trimellitic anhydride toxicity, bone marrow transplantation, and mitral stenosis.
Diagnosis: Diffuse pulmonary hemorrhage (Goodpasture's syndrome)
Diagnostic features of diffuse pulmonary hemorrhage on HRCT
Comparison of inspiratory/expiratory images: For more information, see Case Study 18 for air trapping and abnormal ground-glass, Case 28 for air trapping, and Case 29 for inhomogeneous lung density due to vascular disease.
Note that the density of the entire lung increases at end-expiration compared to end-inspiration. The normal (dark) regions of lung become lighter in appearance at end-expiration, and the abnormal, ground-glass densities also become lighter at end-expiration (dark gets lighter, light gets lighter).
PMNs in capillary wall, indicating a capillaritis
Linear deposit of immunoglobulin in alveolar wall, indicating a diagnosis of Goodpasture's syndrome
1. Bilateral, symmetric, homogeneous ground-glass opacity and centrilobular ground-glass nodules.
2. The ground-glass opacity is located in the peripheral and mid-lung zones and spares the central portion. At the periphery of the confluent, ground-glass opacity in the anterior right lung, note regions of centrilobular, ground-glass nodules.
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