Table 1.

Histological types of parotid tumor

	Histological changes
1.	Loss of polarity of basal cells
2.	More than one layer of cell with basaloid appearance
3.	Drop-shaped rete-ridges
4.	Increased nuclear-cytoplasmic ratio
5.	Nuclear hyperchromatism
6.	Enlarged nucleoli
7.	Increased number of mitotis
8.	Abnormal form of mitosis
9.	The presence of mitotic cells in the superficial epithelium
10.	Cellular and nuclear pleomorphism
11.	Irregular epithelial stratification
12.	Loss of intercellular adherence
13.	Keratinization of single cells or cell groups in the prickle cell layer