Maspin expression in normal and neoplastic salivary gland

BACKGROUND: Maspin inhibits cell motility, invasion and metastasis. Loss or reduction in maspin expression has been associated with tumoral progression. METHODS: The presence of maspin was studied immunohistochemically in salivary gland tumours presenting cells with myoepithelial differentiation in their composition, and in normal salivary gland. RESULTS: Pleomorphic adenoma (PA) presented high expression of maspin, except in the spindle cells and occasional luminal cells. Epithelial-myoepithelial carcinoma and tubular adenoid cystic carcinoma (ACC) showed intense expression in all cells. Cribriform ACC evidenced only few positive cells of the luminal type, while solid subtype showed rare positive cells. Normal salivary gland tissue has shown low levels of maspin positivity. CONCLUSIONS: Maspin has small participation in normal salivary gland, is increased in PA, and decreases as the histological malignancy raises. Hence, in salivary gland, its expression is not exclusive of myoepithelial cells; thus, it should not be used as a marker for this cell. Nevertheless, we believe it is an important marker of biological behaviour in these tumours.