Pathologists and other doctors use the term lesion to describe any abnormal area of tissue. A lesion can be caused by many different things, including injury, infection, inflammation, or a growth such as a tumour. The term does not specify what is causing the abnormality or whether it is harmful. Instead, it simply means that the tissue looks different from normal.
“Lesional” is an adjective that refers to something related to or involving a lesion. For example, if a pathologist describes “lesional tissue,” they are referring to the part of the tissue that shows the abnormality.
Are all lesions tumours?
No, not all lesions are tumours. A tumour is a specific type of lesion involving abnormal cell growth. Tumours can be benign (noncancerous) or malignant (cancerous). However, lesions can also include other types of abnormalities that are not tumours. For example:
- Inflammatory lesions can result from an infection or immune response, such as a swollen lymph node during a throat infection.
- Traumatic lesions are caused by physical injury, such as a cut or bruise on the skin.
- Degenerative lesions can occur when tissue breaks down over time, such as in arthritis.
- Pre-cancerous lesions are areas of tissue that show changes that might eventually turn into cancer, such as in squamous intraepithelial lesions of the cervix.
So, while all tumours are lesions, not all lesions are tumours.
What are some examples of common types of lesions in pathology?
Pathologists encounter many different types of lesions in their work. Here are some examples:
- Skin lesions: These include moles and rashes. Some skin lesions may be harmless, while some, like melanoma, can be serious.
- Oral lesions: Sores or patches in the mouth, such as those caused by oral thrush or leukoplakia, are common examples.
- Liver lesions: These can range from benign cysts to malignant tumours like hepatocellular carcinoma.
- Lung lesions: Areas of abnormality seen on imaging may represent infections, scars, or tumours such as lung cancer.
- Bone lesions: These include abnormalities such as fractures, cysts, or tumours like osteosarcoma.
- Breast lesions: These can range from benign conditions like fibrocystic changes to malignant tumours like invasive ductal carcinoma.
Each type of lesion needs to be evaluated carefully to determine what it represents. Pathologists use tools like a microscope, special stains, and molecular tests to make the final diagnosis.