The cancers most likely to invade the pericardium are lung cancer, breast cancer, and lymphoma. Cardiac tamponade occurs suddenly when so much fluid accumulates that the heart can't beat normally. Before the onset of tamponade, the person usually feels a vague pain or pressure in the chest that worsens upon lying down and gets better upon sitting up. Doctors diagnose cardiac tamponade with chest x-rays, electrocardiograms, and echocardiograms. A sample of the fluid is examined under a microscope to see whether it contains cancer cells.
Additional treatment depends on the type of cancer present.
Fluid can accumulate in the pleural sac for many reasons, one of which is cancer. A doctor drains the fluid by inserting a syringe needle between the ribs into the pleural sac. If fluid starts to accumulate again rapidly after this procedure, the doctor inserts a drainage tube through the chest wall and leaves it in the pleural sac until the person's condition improves. Special chemicals may be inserted into the pleural sac to irritate its walls, inducing them to fuse together. This eliminates the space where fluid can enter and reduces the likelihood of a recurrence.