Yes... it can. It isn't common but it can happen. With the lungs at least. Sometimes depending on the severity a fungal infection can spread to the lungs (Fungal infection = Immunodepressed - there are a variety of other things that go hand in hand with this but this can be a major cause). Where the fluid around the heart is concerned it can be caused by inflammation. Now I know you've had a few things going on. You are a new mom, (relatively) you work, you've battled oral cancer, and I think recently you had a bit of a chest infection/cold? this in my books = STRESS - which can seriously impact your immune system. Are any of your meds - if you are taking any - steroids? This too can mask issues - often time it will cure the symptom but not the problem and masks issues.

are they removing the necrotic and granulation tissue?