help! Bronchial Adenoma, Lung Mass Lesion Lobe

My husband has just come back from his Bronchoscopy as was told this was what he had in is lower left lung completely occluding his lower lobe bronchus. What is it,? They said he will need surgery what will this involve and how big is the surgery? Just concerned as am 32 weeks pregnant and concerned it might be slap bang in the middle of things as was 3 weeks early with my first and hes concerned with how long it will take for recovery etc.