Carcinoma in situ

Carcinoma in situ (CIS) is an early form of carcinoma defined by the absence of invasion of surrounding tissues. In other words, the neoplastic cells proliferate in their normal habitat, hence the name 'in situ' (Latin for 'in its place'). For example, carcinoma in situ of the skin, also called Bowen's disease is the accumulation of neoplastic epidermal cells within the epidermis only.
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Carcinoma in situ n. A neoplasm whose cells are localized in the epithelium and show no tendency to invade or metastasize to other tissues. [more]Carcinoma in situ - Community and Resources

Noun
1. a cluster of malignant cells that has not yet invaded the deeper epithelial tissue or spread to other parts of the body
(synonym) preinvasive cancer
(hypernym) carcinoma

Cancer that involves only the cells in which it began and that has not spread to other tissues.

[KAR-si-NO-ma in SYE-too]
Cancer that involves only cells in the tissue in which it began and that has not spread to nearby tissues.