NCIt definition : A general term used to describe carcinomas arising from epithelial cells that have
been transformed into another cells type (metaplastic epithelial cells). A representative
example is the adenocarcinoma arising in Barrett esophagus. This term is also used
to describe carcinomas in which the malignant epithelial cells show differentiation
towards another cell type. A representative example of the latter is the metaplastic
breast carcinoma in which the malignant glandular cells show squamous, spindle cell,
or chondroid/osseous differentiation.;
Alternative definition : NCI-GLOSS: A general term used to describe cancer that begins in cells that have changed
into another cell type (for example, a squamous cell of the esophagus changing to
resemble a cell of the stomach). In some cases, metaplastic changes alone may mean
there is an increased chance of cancer developing at the site.;