Pulmonary histiocytosis X - imaging aspects of pulmonary involvement

Pulmonary histiocytosis X is an idiopathic disease which is and uncommon but important cause of pulmonary fibrosis in young adults. Chest radiographs and high resolution computed tomographic (HRCT) scans of the lungs of 7 patients diagnosed as pulmonary histiocytosis X were examined retrospectively. The authors reviewed the pathologic, clinical and radiographic features of pulmonary histiocytosis X, focusing on differential diagnosis and disease progression. Pulmonary histiocytosis X can be suspected on the basis of chest radiographic findings; predominantly upper lobe nodules and cysts present an increased sensitivity and are virtually pathognomonic of this disorder. Chest HRCT allows good assessment of the evolution of pulmonary histiocytosis X and is also valuable in distinguishing histiocytosis from other disorders that produces nodules or cysts. (author)