Myoepithelial Cells in Salivary Gland: Physiology to Pathology

In salivary glands, the secretory portion are embraced by contractile cells which lie between the secretory cells and the basement membrane. The contractile mechanism of these cells is thought to be similar to that of muscle cells and has given rise to the term myoepithelial cells. The myoepithelial cells are stellate or spiderlike, with a flattened nucleus, scanty perinuclear cytoplasm and long branching processes that embrace the acini and intercalated duct cells. Salivary gland tumors are the most histologically heterogeneous group of tumors with greatest diversity of morphological features among their cells and tissues. The neoplastic myoepithelial cells are considered as a key cellular participant in morphogenetic appearances of many salivary gland tumors. Myoepithelial cells produce an extracellular matrix such as basement membrane material and myxoid substances leading to diverse histology of salivary gland tumors. They may also exert an anti invasive effect in a neoplasm promoting epithelial differentiation, secreting proteinase inhibitor and suppressing angiogenesis. Thus, this library work is undertaken to review the role of myoepithelial cell in salivary glands.