What is Epithelioid?

Epithelioid is an adjective used to describe a type of cell or tissue that resembles epithelial cells. Epithelial cells are cells that line the outer and inner surfaces of the body, such as the skin, organs, and glands. They form a barrier between the body and the external environment, and they also play a role in the production of hormones and other secretions.

Epithelioid cells are cells that have some characteristics of epithelial cells but do not fully meet the criteria for being true epithelial cells. For example, they may have a more irregular shape or be less tightly packed together than true epithelial cells. They may also have different markers or functions than true epithelial cells.

Epithelioid tissue is tissue that contains a mixture of epithelial and other cell types, such as connective tissue or muscle fibers. It is often found in the basal layers of epithelial tissues, where the cells are more undifferentiated and have a higher proliferative potential.

Examples of epithelioid tissue include:

1. Basal cell carcinoma: This is a type of skin cancer that arises from the basal layer of the epidermis. The tumor cells are epithelioid and have a more irregular shape than normal epidermal cells.
2. Adenoid cystic carcinoma: This is a type of cancer that originates in the salivary glands. The tumor cells are epithelioid and have a characteristic "papillary" growth pattern.
3. Metaplastic carcinoma: This is a type of cancer that arises from a previously normal epithelial tissue, such as the breast or prostate gland. The tumor cells are often epithelioid and have a more aggressive growth pattern than true epithelial cells.

In summary, epithelioid cells and tissue are those that resemble epithelial cells but do not fully meet the criteria for being true epithelial cells. They can be found in various parts of the body and may be associated with different types of cancer.