Table 3.

Definitions of PA

Foote and Frazell [4]	The term “mixed tumor” designates the commonest group of major salivary gland tumors that characteristically show combined traits of epithelial and connective tissue-like growth
Thackray and Lucas [16]	Pleomorphic adenoma is a circumscribed tumor characterized microscopically by its pleomorphic or mixed appearance, and its clearly recognizable epithelial tissue intermingled with areas of mucoid, myxoid, or chondroid appearance
Seifert [29]	A tumor of variable capsulation characterized microscopically by architectural rather than cellular pleomorphism. Epithelial and modified myoepithelial elements intermingle with tissue of mucoid, myxoid or chondroid appearance. The epithelial and myoepithelial components form ducts, strands, sheets or structures resembling a swarm of bees. Squamous metaplasia is found in about 25 % of pleomorphic adenomas
Ellis and Auclair [27]	Mixed tumor is a benign, epithelial-derived tumor composed of cells that demonstrate both epithelial and mesenchymal differentiation
Eveson et al. [30]	Pleomorphic adenoma is a tumor of variable capsulation characterized microscopically by architectural rather than cellular pleomorphism. Epithelial and modified myoepithelial elements intermingle most commonly with tissue of mucoid, myxoid or chondroid appearance