Carcinoma in situ

Carcinoma in situ (CIS) is a term used in medicine to describe a group of abnormal cells. While these cells have the potential to become cancer, they are not yet invasive and therefore are not considered a true cancer. Instead, they are often referred to as pre-cancerous lesions.

Definition

Carcinoma in situ is defined as a group of abnormal cells that are confined to their place of origin. These cells have not yet invaded the basement membrane or other tissues. The term "in situ" is Latin for "in its original place".

Types

There are several types of carcinoma in situ, each named for the type of cells involved and the location in the body where they are found. These include:

• Ductal carcinoma in situ (DCIS): This type of CIS occurs in the milk ducts of the breast.
• Lobular carcinoma in situ (LCIS): This type of CIS occurs in the lobules of the breast.
• Cervical intraepithelial neoplasia (CIN): This is a type of CIS that occurs in the cervix.
• Vulvar intraepithelial neoplasia (VIN): This type of CIS occurs in the vulva.
• Anal intraepithelial neoplasia (AIN): This type of CIS occurs in the anus.

Diagnosis

Carcinoma in situ is often diagnosed through routine screening tests, such as a Pap smear for cervical intraepithelial neoplasia or a mammogram for ductal carcinoma in situ. If these tests detect abnormal cells, further testing may be done to confirm the diagnosis.

Treatment

The treatment for carcinoma in situ depends on the type and location of the abnormal cells. Options may include close monitoring, surgery to remove the abnormal cells, or treatment with radiation or drugs to destroy the cells.

Prognosis

The prognosis for carcinoma in situ is generally good, as these cells have not yet become invasive. However, if left untreated, they may develop into invasive cancer.

See also

• Cancer
• Oncology
• Pathology