Thank you so much for replying. She's had cytology done twice (thoracentiesis was done twice) and they checked both times for cancer. I think they were about 2 months apart. But she has not had a CT, just chest X-rays, so we will look into it further. Thanks again for your advice and Happy Holidays.
I'm sorry to hear your grandmother is having some trouble. Pleural effusions can be caused by a number of conditions. I'm not sure what work your grandmother's physician has done to diagnose the etiology of the effusion. If it is TRULY transudative, the most common causes are heart disease, liver disease, and kidney disease. If it is exudative, the number of causes broadens. If she is elderly and was a smoker, malignancy is at the top of the list. If her initial thoracentesis was negative for malignancy, you may want to ask about repeating the cytology and getting a CT scan of the chest to rule out cancer. Other causes include pulmonary embolism, rheumatoid arthritis, lupus. It is true the blood thinner is likely contributing to the color change in the fluid, but again make sure your doctor isn't missing a malignancy. Hope this helps.