Infantile pulmonary hypertension associated with foreign body vasculitis.

An infant dying with pulmonary hypertension had a pulmonary vessel foreign body vasculitis as identified by light microscopy and characterized ultrastructurally by scanning electron microscopy and energy-dispersive x-ray analysis. The inclusions were of two distinct types: those containing silicon and titanium, and others consisting of talc. The possible sources of these inclusions and the importance of considering foreign body vasculitis in the pathogenesis of clinically idiopathic pulmonary hypertension are discussed.