Show All Definitions
Oncogene
A mutated gene that promotes the development of a neoplasm in one of several ways (e.g. promoting growth factor independence, inhibiting apoptosis, stimulating proliferation, etc).
Apoptosis
"Programmed-cell death" which is disrupted through genetic mutation in neoplasms promoting unrestrained cellular division (immortalization).
Neoplasm
A mass resulting from the autonomous growth of a monoclonal population of cells as a consequence of genetic mutation.
Tumor
A synonym for neoplasm. Historically it has referred to any swelling (e.g. from inflammation).
Benign
A neoplasm that doesn't metastasize and generally doesn't kill the patient.
Malignant
A tumor which is locally invasive and/or capable of metastasizing, giving it the capacity to kill the patient.
Dysplasia
A premalignant changes resulting from genetic mutations that are a precursor to the development of malignancy (although not all dysplasia progress).
In situ carcinoma
Often also referred to as 'high grade dysplasia' this is a pre-invasive form of cancer in epithelium that has not (yet) developed the ability to erode through the basement membrane surrounding the structure (epithelial surface, duct) in which it develops.
Adenoma
A benign epithelial neoplasm (e.g. colonic adenoma, pituitary adenoma, renal tubular adenoma, adrenal adenoma) which may or may not have the capacity to develop into a malignant tumor.
Invasion
A hallmark of malignancy, in which tumor cells have the ability to erode through basement membranes, stroma, normal parenchyma, or visceral membranes.
Desmoplasia
The reactive host-derived fibroblastic stroma that surrounds an invasive tumor. Originally thought to be merely a reaction to tumor invasion, desmoplastic stroma is now known to be an important stimulatory component of many tumors (despite the fact that it, itself is non-malignant).
Angiogenesis
The ability of a tumor to induce the development of a blood-supplying neovasculature into the tumor. Although seen in benign tumors, it is a requirement for the development of malignant tumors.
Anaplasia
Exaggerated pleomorphism with the markedly disturbed growth of tumor cells in disorganized masses.
Pleomorphism
Variation in the size and shape of cells and nuclei.
