Which term describes a collection of pus surrounded by inflamed tissue?

• A. Abscess
• B. Ulcer
• C. Cyst
• D. Furuncle

Answer: (A)

A localized pocket of pus within tissue, surrounded by inflamed tissue, is called an abscess. It forms when an infection triggers an influx of neutrophils and dead cells that pool into a cavity, and the body walls this area off with inflammatory tissue, sometimes developing a fibrous capsule. This results in a swollen, tender, warm lump that may drain through the skin. An ulcer is a loss of tissue with a crater-like opening, not a contained pus-filled cavity. A cyst is a closed sac that may contain fluid or semi-solid material, not typically purulent, and not defined by an inflammatory pus pocket. A furuncle, or boil, is a specific type of abscess centered on a hair follicle, usually involving deeper skin layers; the general term for the described lesion is abscess.