<prompt> Most common cause of pleural effusion in HIV patients includesMycobacterium tuberculosis infectionP Carinii infectionLymphomKaposis sarcoma  <response>: D Kaposis sarcoma AIDS Pleural effusions are uncommon in such patients. The most common cause is Kaposis sarcoma, followed by parapneumonic effusion. Other common causes are TB, cryptococcosis, and primary effusion lymphoma. Pleural effusions are very uncommon with Pneumocystis carinii infection. 