Pathology dictionary -
A neoplasm is an abnormal growth of cells that push normal tissue out of the way as it grows. Most neoplasms start from a single abnormal cell that divides many times before it is noticed by the patient. Another word for neoplasm is tumour.
Neoplasm does not mean the same thing as cancer. If a neoplasm is made of cells that do not have the ability to enter (invade) other tissues or travel (metastasize) to other parts of the body, it is considered to be a non-cancerous (benign) growth.
However, when the cells in a neoplasm have the ability to enter the surrounding tissue or to travel to distant body sites, it is considered a cancer (a malignant tumour). Other features that are usually only seen in cancers include perineural invasion and lymphovascular invasion.