What is a local area of pus and infection called?

An area of pus and infection that is localized within tissue is referred to as an abscess. This condition typically arises when bacteria invade a particular area of the body, leading to the accumulation of white blood cells, dead tissue, and bacteria, resulting in pus. Abscesses often present as swollen, painful lumps and can develop in various body parts, including the skin, organs, and even within cavities.

In contrast, a fistula is an abnormal connection between two hollow spaces, such as organs or vessels, and is not specifically defined by the presence of pus. A cyst is a closed sac-like structure that can be filled with fluid, gas, or solid material, but it does not inherently indicate infection. A lesion refers to any abnormal change in tissue, which could be due to a variety of causes, including infection, but does not specifically denote an area of pus or localized infection.

Thus, while all the other terms may relate to various types of tissue abnormalities, an abscess specifically identifies a localized collection of pus due to infection, making it the correct answer.