Dysplasia can be low-grade or high-grade. High-grade dysplasia may also be referred to as carcinoma in situ. Invasive carcinoma, usually simply called cancer, has the potential to invade and spread to surrounding tissues and structures, and may eventually be lethal. Examples
Cervical squamous intraepithelial lesion (SIL), previously called cervical intraepithelial neoplasia (CIN), is a form of dysplasia that can progress to cervical cancer. The term carcinoma in situ may be used interchangeably with high-grade SIL. Ductal carcinoma in situ of the breast is the most common precancer in women. Bowens disease is a squamous carcinoma in situ of the skin. Colon polyps often contain areas of CIS that will almost always transform into colon cancer if left untreated. High-grade prostatic intraepithelial neoplasia is equivalent to CIS of the prostate. Bronchioloalveolar carcinoma (BAC) of the lung is the only form of CIS that can kill directly because, in rare cases (the "pneumonic form"), it expands greatly and fills the lungs, preventing breathing and causing other dire effects on the host. Thus, the pneumonic form of BAC is a true malignant entity, but is not "invasive" in the classical sense. For this reason, it is considered a form of CIS by pathologists, but not by oncologists or surgeons, and inclusion of this form of cancer among the types of CIS is controversial. Treatment
Carcinoma in situ is, by definition, a localized phenomenon, with no potential for metastasis unless it progresses into cancer. Therefore, its removal eliminates the risk of subsequent progression into a life-threatening condition.
In contrast, in 1993, the 
Eleventh Circuit Court of Appeals upheld the Atlanta fire departments "no-beard" policy because it was justified by a "business necessity", in that case the fact that even short beards interfered with firefighters use of self-contained breathing apparatus. See also
Laser hair removal
List of cutaneous conditions

References


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