Pleural effusion is a condition characterized by accumulation of fluid not normally present in the pleural cavity. If the accumulated fluid exceeds more than 300 mL, certain clinical findings appear including decreased tactile fremitus and asymmetrical chest expansion. These signs are considered to be the most reliable observations for pleural conditions. Cough and egophony may also be present, but are less specific. Lymphadenopathy is one of the extrapulmonary signs that suggests malignancy.