Q; Which tumors are more prone to give negative cytology in malignant pleural effusion?

Answer:

Generally cytology is positive only in approximately 60 percent of malignant pleural effusions, but following tumors are more prone to have negative cytology.

• mesothelioma,
• sarcoma, and
• lymphoma

Other factors which effects the cytology of malignant effusion are the tumor burden in the pleural space, amount of pleural fluid submitted and the expertise of the cytologist.

Usually 10 mL of pleural fluid should be adequate for cytologic processing.

References:

1. Maskell NA, Butland RJ, Pleural Diseases Group, Standards of Care Committee, British Thoracic Society. BTS guidelines for the investigation of a unilateral pleural effusion in adults. Thorax. 2003;58(suppl 2):ii8–17.

2. Sallach SM, Sallach JA, Vasquez E, Schultz L, Kvale P. Volume of pleural fluid required for diagnosis of pleural malignancy. Chest. 2002;122:1913–7.