What type of lesions cast a shadow within their edges, such as lacerations or ulcers?

Depressed lesions are characterized by a loss of tissue that results in a shadow being cast by their edges. This occurs because these lesions are below the level of the surrounding skin, which leads to an area of lighter color and shadow as the light hits the surface of the skin. Common examples of depressed lesions include lacerations and ulcers, where the skin is no longer at its normal level due to injury or disease. These types of lesions differ markedly from elevated lesions, which protrude above the skin surface, thus not casting shadows in the same way, and from flat lesions, which lie at the same level as the surrounding skin. Benign lesions encompass a broader category of growths that may not necessarily include the shadow-casting feature associated with tissue loss.