Idiopathic cholesterol pneumonitis.

The fiftieth case of idiopathic cholesterol pneumonitis (ICP) is presented and the 49 previously reported cases have been reviewed. This review draws attention to certain features which have not previously been emphasized, including marked male predominance, single lobe involvement, the distribution of the lesions, dense pleural fibrosis, smoking history and the close histological association between giant cells and disrupted elastic fibres of the alveolar walls. The clinical and radiological similarity between ICP and primary bronchogenic carcinoma is described. Various aetiology theories are discussed, and the similarity between ICP and spontaneous lipid pneumonia in the mongoose is noted; the hypothesis is put forward that ICP, like the mongoose pneumonia, is an expression of disordered production or disposal of excessive surfactant.