Discussion
Diagnosis With Brief Discussion
- Diagnosis
- Subacute hypersensitivity pneumonitis
- Radiologic Findings
- Fig 1. Chest radiograph shows diffuse ground-glass opacities (GGO) and ill-defined nodular opacities in both lungs.
Fig 2-3. High resolution CT demonstrates bilateral diffuse GGOs and numerous small ill-defined centrilobular nodules in both lungs with discrete lobular area of decreased attenuation in both lower lobes.
Figs 4-5. Follow up HRCT at 2 month after corticosteroid therapy and removal from exposure shows decreased extent of geographic GGOs and small ill-defined centrilobular nodules.
Figs 6-7. Another follow up HRCT at 1 year after first HRCT shows progression of geographic GGOs and small ill-defined centrilobular nodules in both lungs with discrete lobular area of decreased attenuation in both lower lobes.
In bronchoalveolar lavage (BAL) fluid, the percentage of lymphocyte was 40% and CD4/CD8 ratio was 0.7. She is a Buddhist monk who built roof tile in a temple. Her symptoms and radiologic findings have gradually improved after initiation of corticosteroid therapy but aggravated after discharge and return to the temple.
Fig 4-5. after 2 months steroid therapy
Fig 6-7. after 1 year
- Brief Review
- Hypersensitivity pneumonitis (HP) refers to a constellation of granulomatous, interstitial, bronchiolar, and alveolar filling pulmonary diseases caused by repeated exposure and sensitization to a variety of organic and chemical antigens. Early recognition of the disease and prevention of long term antigen exposure are necessary to avoid progression to irreversible fibrosis.
HP traditionally has been classified as manifesting in three phases: acute, subacute, and chronic. Subacute HP is caused by intermittent or continuous exposure to low doses of antigen. The symptoms may appear gradually over weeks or months. Patients usually present with exertional dyspnea and cough.
Chest radiographs obtained in many patients with HP are normal. Abnormal radiographic findings observed in some patients include numerous poorly defined small (less than 5 mm) opacities throughout both lungs, sometimes with sparing of the apices and bases. Airspace disease is represented often as GGO (which can be patchy or diffuse, resembling pulmonary edema) or, more rarely, as consolidation.
HRCT has greatly improved the radiologic diagnosis of HP: abnormalities are seen in more than 90% of patients. Typical findings of subacute HP include patchy bilateral GGO and small ill-defined centrilobular nodules. Another common manifestation of subacute HP is the presence of focal areas of decreased attenuation on inspiratory HRCT, air trapping on expiratory HRCT, or both. These areas usually have sharply defined margins and a configuration consistent with involvement of single or multiple adjacent pulmonary lobules.
In the presence of a history of exposure and consistent clinical and radiologic findings, the diagnosis of HP can be confirmed by visualization of increased numbers of lymphocytes in BAL fluid and occasionally by findings at transbronchial biopsy.
Most cases of HP, whether acute or insidious, include the following four histologic features in variable amounts and combinations: cellular bronchiolitis, diffuse chronic interstitial inflammatory infiltrates (primarily consisting of lymphocytes and plasma cells), and poorly circumscribed interstitial nonnecrotizing (noncaseating) granulomas.
- Please refer to
Case 59, Case 271, Case 341, Case 427, Case 462, Case 605, Case 666, -
KSTR imaging conference 2018 Spring Case 8
,
KSTR Imaging Conference 2016 Spring Case 10
,
Thoracic Imaging 2003- Korean & Japanese Film Interpretation - Case 7
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KSTR Imaging Conference 2001 Spring Case 15,
- References
- 1. C. Isabela S. Silva, Andrew Churg, Nestor L. M
- Please refer to
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- Keywords
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lung, Subacute Hypersensitivity Pneumonitis ,