Which of the following is a neoplastic condition in which malignant cells have not invaded across the cellular basement membrane?
A. MetaplasiaAnswer D
Carcinoma in situ (CIS) is a flat, non-invasive neoplastic condition in which the cancerous cells have not invaded through the basement membrane of the cell. The basement membrane of a cell provides structural support and forms a selective barrier between the cell and the surrounding tissue. Once the cancer cells reach beyond the basement membrane, an invasive neoplasia is formed. In most cancers, CIS is pre-malignant; however, in bladder CIS it is considered to be a pre-invasive papillary cancer in which there is a greater than 50% chance of progression into invasive disease.