pulmonary disorders
Pulmonary Langerhans Cell Histiocytosis
Diagnosis of PLCH
High-resolution CT (HRCT) Pulmonary function tests Sometimes bronchoscopy and biopsy Pulmonary Langerhans cell histiocytosis is suspected based on history and chest x-ray and is confirmed by HRCT and bronchoscopy with biopsy and bronchoalveolar lavage. Chest x-ray classically shows bilaterally symmetric nodular opacities in the middle and upper lung fields with cystic changes and normal or increased lung volumes. The lung bases are often spared. Appearance may mimic Chronic Obstructive Pulmonary Disease (COPD) (COPD) or Confirmation on HRCT of middle and upper lobe cysts (often with bizarre shapes) and/or nodules with interstitial thickening is considered diagnostic of PLCH. Overview of Tests of Pulmonary Function findings are normal, restrictive, obstructive, or mixed depending on when the test is done during the course of the disease. Most commonly, the diffusing capacity for carbon monoxide (DLCO) is reduced and exercise is impaired. Bronchoscopy and biopsy are indicated when imaging and pulmonary function tests are inconclusive. Finding>5% of CD1a cells in bronchoalveolar lavage fluid is highly suggestive of the disease. Biopsy shows proliferation of Langerhans cells with occasional clustering of eosinophils (the origin of the outdated term eosinophilic granuloma) in the midst of cellular and fibrotic nodules that may take on a stellate configuration. Immunohistochemical staining is positive for CD1a, S-100 protein, and HLA-DR antigens. 