evaluation of adenoid cystic carcinoma and polymorphous low-grade adenocarcinoma by immunohistochemistry

background and aim: salivary gland tumors classification continuously undergoes alternations, especially in the recent years. this study used immunohistochemical markers for distinguishing between polymorphous low-grade adenocarcinoma (plga) and adenocarcinoma carcinoma (adcc) which have several overlapping histological and clinical features. materials & methods: ten adcc and eight plga with five normal minor salivary glands were selected after review by two oral pathologists. lsab method was used for seven markers: carcinoembryonic antigen, epithelial membrane antigen, muscle specific actin, vimentin, s100, p53 and ki-67. finally, the data were analyzed by mann-whiteny test. results: analysis of data showed a high expression of cea, ema and ki-67 in adcc compared to plga. although, cea (p<0.001) expression was limited to luminal cells .in contrast, msa (p=0.034) expression in nonluminal cells, and ki-67 (p<0.001) occurred in both luminal and nonluminal cells. also there was highly expression of vimentin and s-100 in plga with no significancy for ema and tp53. conclusion: the result of this study suggests that ich can be a helpful tool. the immunostaining of adcc and plga with cea, vimentin and ki-67 were of greater significant, s100 and msa were less significant and the others (ema and p53) could not offer an adjunctive aid in differential diagnosis between the two tumors. j dent sch 2008 26(4): 3