Myoepithelial cell

Myoepithelial cells are specialized cells found in glandular tissue, particularly in the mammary gland, salivary gland, and sweat glands. These cells play a crucial role in the function of these glands by aiding in the expulsion of glandular secretions.

Structure

Myoepithelial cells are characterized by their unique structure, which combines features of both muscle cells and epithelial cells. They are typically located between the basement membrane and the secretory cells of the glandular epithelium. These cells have a stellate or spindle shape and contain actin and myosin filaments, which are essential for their contractile function.

Function

The primary function of myoepithelial cells is to contract and facilitate the expulsion of secretions from the glandular acini into the ducts. This process is particularly important in the mammary gland during lactation, where the contraction of myoepithelial cells helps in the ejection of milk.

Location

Myoepithelial cells are found in various exocrine glands, including:

• Mammary glands
• Salivary glands
• Sweat glands
• Lacrimal glands

Clinical Significance

Myoepithelial cells are significant in the diagnosis and study of various pathological conditions. They can be involved in the development of certain types of tumors, such as myoepitheliomas and adenoid cystic carcinomas. The presence or absence of myoepithelial cells can also be a diagnostic marker in distinguishing between benign and malignant glandular lesions.

Histology

In histological sections, myoepithelial cells can be identified by their location and their characteristic staining properties. They often stain positively for smooth muscle actin (SMA), calponin, and p63.

Research

Ongoing research is focused on understanding the role of myoepithelial cells in glandular development, function, and disease. Studies are also exploring their potential role in cancer progression and as targets for therapeutic intervention.

See also

• Epithelial cell
• Muscle cell
• Gland
• Lactation
• Tumor