The frequency and distribution of mast cells in pleomorphic adenomas of salivary glands.

Aim: To investigate whether the frequency and distribution of mast cells (MCs) in pleomorphic adenomas (PAs) of major and minor salivary glands justifies the suggestion that there exists an association between MCs and mucoid stromal changes in PAs.

Methods: The material consisted of 22 cases of pleomorphic adenoma (eight arising in major and 14 in minor salivary glands) and a control group represented by five cases of monomorphic adenoma (MA). Representative 3-microm thick, paraffin-embedded sections were stained with H&E and Azur A.