Lesion - Types

Types

Because the definition of a lesion is so broad, the varieties of lesions are virtually endless. Lesions can occur anywhere in the body that consists of soft tissue or osseous matter, though most frequently found in the mouth, skin, and the brain, or anywhere where a tumour may occur. They are subsequently classified by their features. If a lesion is caused by a tumor it will be classified as malignant or benign. Lesions may be classified by the shape they form, as is the case with many ulcers, which can have a bullseye or 'target' appearance. Their size may be specified as gross or histologic depending on whether they are visible to the unaided eye or require a microscope to see.

An additional classification that is sometimes used is based on whether or not a lesion occupies space. A space-occupying lesion, as the name suggests, has a recognizable volume and may impinge on nearby structures, whereas a non space-occupying lesion is simply a hole in the tissue, e.g. a small area of the brain that has turned to fluid following a stroke.

Some lesions have specialized names, such as Ghon lesions in the lungs of tuberculosis victims. The characteristic skin lesions of a varicella-zoster virus (VZV) infection are called chickenpox. Lesions of the teeth are usually called dental caries.

Another type of lesion is excitotoxic lesions that can be caused by excitatory amino acid like kainic acid that kills neuron by stimulating to death.

Sham lesions are the process of putting stereotaxic apparatus and insert it inside the skull to produce a lesion to see if behavior correlates with the brain lesion.

Finally, lesions are often classified by their location. For example, a 'skin lesion' or a 'brain lesion'.