| Empyema | |
|---|---|
| Classification and external resources | |
| ICD-10 | J86.9 | 
| MedlinePlus | 000123 | 
| MeSH | D004653 | 
An empyema (from Greek ἐμπύημα, "abscess") is a collection or gathering of pus within a naturally existing anatomical cavity. For example, pleural empyema is empyema of the pleural cavity. It must be differentiated from an abscess, which is a collection of pus in a newly formed cavity.
In human medicine, empyema occurs in: