By Dr Ananya Mandal, MD
The term neoplasm refers to an abnormal mass of tissue arising from an abnormal proliferation of cells.
The body is made up of trillions of cells that grow, divide, and die in an orderly fashion. This process is a tightly regulated one that is controlled by the DNA machinery within the cell. When a person is growing up, the cells of the body rapidly divide, but once adulthood is reached, cells generally only divide to replace worn-out, dying cells or to repair injured cells.
Neoplasia describes when these cells proliferate in an abnormal manner that is not coordinated with the surrounding tissue. As this excessive growth persists, a lump or tumor is usually formed.
The different types of neoplasm include:
Benign or non-cancerous
Benign neoplasms are non-cancerous forms of tissue proliferation such as skin moles, lipomas or uterine fibroids. These neoplasms do no not become cancerous and mainly cause problems due to their space-occupying nature.
Pre-malignant or pre-cancerous
Precancerous neoplasms are masses that have the potential to become cancerous. The earliest form of precancer is dysplasia. The cells proliferate only in their site of origin and do not spread. However, dysplasia may become high-grade and develop into carcinoma in situ which carries a high risk of turning into cancer.
Malignant or cancerous
These terms are used to describe neoplasms that have become cancerous, as defined by the following distinct features:
Abnormal cell growth
Capacity to invade other tissues
Capacity to spread to distant organs via blood vessels or lymphatic channels (metastasis)
These cancers have the capacity to take over the whole body and eventually kill the host.
Reviewed by Sally Robertson, BSc