An upright chest film of a cachectic, homeless 47-year-old woman shows blunting of the right costophrenic angle. The following is/are true:

a. A lateral decubitus film should be obtained to confirm the presence of fluid rather than a CT scan

e. Pleural fluid cytology report of lumphoma should be viewed with skepticism

Although the CT scan is a very sensitive indicator of pleural effusion, a lateral decubitus is the simplest way to differentiate fluid from pleural thickening or fibrosis. Tuberculous pleuritis is difficult to diagnose by stain or culture which have a 30% yield, but the diagnosis is facilitated by needle biopsy of the pleura. Pleural fluid glucose lower than in serum is characteristic of rheumatoid arthritis, neoplasms, and tuberculosis as well as empyema. A red-tinged fluid can occur from needle trauma, but even frankly bloody fluid in this patient may reflect trauma as well as underlying malignancy. Pleural inflammation induces reactive changes in mesothelial cells that makes them resemble lymphocytes, so a lymphoma diagnosis is suspect.