Which term refers to a small rounded projection on the skin?

The term "tubercle" specifically describes a small rounded projection or bump on the skin. This can occur due to various factors, such as inflammation or the formation of a compact mass of tissue. Tubercules can be a normal part of the skin structure, or they can signify an underlying condition but are universally recognized as protrusions.

In contrast, a cyst refers to an enclosed sac filled with fluid or semi-solid material that can appear under the skin, while a lesion is a broader term that encompasses any abnormal change in the skin, including sores, rashes, or tumors. A follicle refers to the small organs in the skin that produce hair and are not characterized as rounded projections. Understanding these distinctions highlights why "tubercle" is the correct term to define a small rounded projection.