What is benign asbestos pleural effusion?

Pleural involvement is hallmark of asbestos exposure (not seen in other ILD) usually small unilateral effusions occur before onset of interstitial disease. Duration is variable 5.5 years to 28 years (between exposure at onset of BAPE: 15 yrs - 46 yrs) Earlier onset is correlated with high-moderate exposure. May resolve spontaneously over weeks to months, can recur on same or opposite sides in 30% of individuals. As it regresses, it may be seen in costophrenic angle with diffuse thickness of pleura. No increased mesothelioma