<unk>  is rare, difficult to diagnose, and probably frequently misdiagnosed as idiopathic pulmonary arterial hypertension. Prevalence in parts of Europe is estimated to be 0.1-0.2 cases per million.<unk>  appears to occur as frequently in men as in women, and age at diagnosis ranges from 7–74 years with a median of 39 years.<unk>  may occur in patients with associated<unk> s such as HIV, bone marrow transplantation, and connective tissue<unk> s.<unk>  has also been associated with several chemotherapy regimens such as bleomycin, BCNU, and mitomycin.
Pulmonary venoocclusive disease
Pulmonary alveolar proteinosis
Chronic thromboembolic pulmonary hypertension
Pulmonary sequestration
Bronchiolitis obliterans
Idiopathic pulmonary haemosiderosis
Pulmonary hyalinizing granuloma
Acute eosinophilic pneumonia