What is the term for a lesion that indicates erosion?

The term that refers to a lesion indicating erosion is an ulcer. An ulcer is characterized by a break in the skin or mucous membrane that can lead to the destruction of underlying tissues. This erosion allows for a loss of the outer layer, which can expose the underlying structures, leading to inflammation and various degrees of tissue damage.

Ulcers can form in various parts of the body, including the stomach (e.g., peptic ulcers) and on the skin (e.g., decubitus ulcers). The erosion of tissue involved with ulcers distinguishes them from other types of lesions.

Granulomas, while they involve localized inflammation, represent a collection of macrophages and do not specifically denote erosion or loss of tissue in the same manner. Phlegmon refers to a diffuse inflammatory process, often related to infections, characterized by the spread of purulent material through tissue but doesn't signify erosion as an ulcer does. Pustules are small, raised areas on the skin filled with pus, indicating localized infection rather than erosion. Thus, the correct term for a lesion that indicates erosion is indeed an ulcer.