Immunohistochemical Expression of Metallothionein in Adenoid Cystic Carcinoma

Objectives:The aim of this study was to search for Metallothionein (MT) in Adenoid Cystic Carcinoma (ACC) and to analyse the possible morphological and quantitative differences among the solid, cribriforme and tubular histological subtypes of ACC. Methods:The presence of MT was investigated in 15 ACC, using the immunohistochemistry technique. Statistical tests were performed with the Biostat 2.0 software. Results: MT was expressed in all cases of ACC, specially in the solid subtype tumor. There was a statistical significant difference on the percentual of labelled cells between the solid and tubular histological subtypes and between the cribriforme and tubular histological subtypes. We noted a predominant expression in myoepithelial cells, with morphological differences following the distribution of mioepithelial cells in the tumors. Conclusions:Our results show that MT may be an important tool on immunohistochemistry diagnosis of myoepithelial tumor cells and that itxs expression depends on the ACC histological subtype analyzed. It also suggests a role for MT in determination of prognosis of ACC. However this topic must be better investigated.