A malignant neoplasm is composed of cells that look less like the normal cell of origin. It has a higher rate of proliferation. It can potentially invade and metastasize. Malignant neoplasms derived from epithelial cells are called carcinomas. Those derived from mesenchymal (connective tissue) cells are called sarcomas. Malignant brain neoplasms and neoplasms of the immune system are special categories with complex nomenclature.
Thus, characteristics of malignant neoplasms include:
More rapid increase in size
Less differentiation (or lack of differentiation, called anaplasia)
Tendency to invade surrounding tissues
Ability to metastasize to distant tissues
Cytologic features of malignant neoplasms include: