What is the term for an area of necrosis where dead cells are sloughed from a free surface?

The term for an area of necrosis where dead cells are sloughed from a free surface is referred to as an ulcer. An ulcer represents a localized loss of tissue, and it typically occurs on the surface of an organ or tissue where the necrosis has resulted in a disruption that allows for the shedding of dead cellular material. This process often reflects underlying pathological changes and can be associated with various conditions, such as infections, inflammatory diseases, or malignancies.

In contrast, while a wound generally refers to any injury to the body's surface and can include cuts or abrasions, it does not strictly pertain to necrosis leading to sloughing off. A lesion is a broader term that encompasses any abnormal tissue change but does not specifically indicate the sloughing process. An abscess, on the other hand, refers to a localized collection of pus resulting from infection and inflammation, rather than tissue necrosis with shedding. Therefore, the specificity of the definition aligns perfectly with the term ulcer, making it the correct choice.