Carcinoma in situ ( CIS ), also known as in situ neoplasm , is a group of abnormal cells. While they are a form of neoplasm, there is disagreement over whether CIS should be classified as cancer. This controversy also depends on the exact CIS being questioned (ie cervix, skin, breast). Some authors do not classify them as cancer, however, admitting that they are potentially cancerous. Others classify certain types as non-invasive forms of cancer. The term "pre-cancer" has also been used.
These abnormal cells grow in their normal places, so " in situ " (from Latin for "in place"). For example, carcinoma in situ in the skin, also called Bowen disease, is the accumulation of dysplastic epidermal cells in the epidermis alone, which fails to penetrate into the deeper dermis. For this reason, CIS usually will not form tumors. In contrast, flat lesions (in the skin, cervix, etc.) or follow the existing organ architecture (in breast, lung, etc.). Exceptions include CIS of the colon (polyps), bladder (preinvasive papilla cancer), or breast (ductal carcinoma in situ or lobular carcinoma in situ ).
Many forms of CIS have a high probability of developing into cancer, and therefore removal may be recommended; However, the development of CIS is known to vary greatly and not all CIS become invasive cancer.
In the TNM classification, carcinoma in situ is reported as TisN0M0 (stage 0).
Video Carcinoma in situ
Terminology
These terms are related because they represent developmental steps toward cancer:
- Dysplasia is the earliest form of precancerous lesions that can be recognized in a biopsy. Dysplasia can be of low quality or high quality. High quality dysplasia can also be referred to as carcinoma in situ .
- Invasive carcinoma, usually just called cancer, has the potential to strike and spread to surrounding tissues and structures, and can eventually be deadly.
Maps Carcinoma in situ
Example
- The cervical intraepithelial squamous lesion (SIL), previously called cervical intraepithelial neoplasia (CIN), is a form of dysplasia that can develop into cervical cancer. The term carcinoma in situ can be used interchangeably with high-quality SIL.
- Ductal carcinoma in situ in the breast is the most common predictor in women.
- Bowen's disease is a squamous skin carcinoma .
- Intestinal polyps often contain areas of CIS that almost always turn into colon cancer if left untreated.
- High-grade intraepithelial prostatic neoplasia is equivalent to CIS prostate.
- Bronchioloalveolar carcinoma (BAC) of the lungs is the only form of CIS that can kill directly because, in rare cases ("pneumonia"), it extends and fills the lungs, prevents breathing and causes other dire effects on the organizer. Thus, the form of BAC pneumonia is a true malignant entity, but not "invasive" in the classical sense. For this reason, it is considered a form of CIS by a pathologist, but not by an oncologist or surgeon, and the inclusion of this form of cancer among CIS types is controversial.
Treatment
Carcinoma in situ is, by definition, a local phenomenon, with no metastatic potential unless it develops into cancer. Therefore, its elimination eliminates the risk of subsequent development into a life-threatening condition.
Some forms of CIS (eg, colon polyps and polypoid tumors of the bladder) may be removed using endoscopy, without conventional surgical resection. Dysplasia of the uterine cervix is ​​removed by excision (cutting) or by burning with a laser. Bowen's disease of the skin is removed by excision. Other forms require major surgery, the best known is intraductal carcinoma of the breast (also treated with radiotherapy). One of the most dangerous forms of CIS is the "form of pneumonia" of the lung BAC, which can require major surgery to remove most of the lungs. When too large, often can not be completely removed, with the development of the eventual disease and death of the patient.
References
Source of the article : Wikipedia
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