OBJECTIVETo examine the role of Epstein-Barr virus (EBV) infection in benign lymphoepithelial lesions with malignant transformation of salivary glands.

METHODS2 cases benign lymphoepithelial lesions with focal malignant transformation (BLEL-FMT), 14 cases of malignant lymphoepithelial lesion (MLEL) and 4 cases of benign lymphoepithelial lesion (BLEL) of salivary glands, 4 cases of nonspecific chronic sialadenitis were examined. Sections were cut from the paraffin blocks and performed in situ hybridization (ISH) for EBV encoded small RNA-1 (EBER-1) using 30-base synthesized oligonucleotide probe and polymerase chain reaction (PCR) for BamHI-W regein of EBV DNA (123 bp).

RESULTSIn ISH, strong signals for EBER-1 were obtained in most of epithelial cell nuclei in examined specimens of BLEL-FMT, no matter in benign or malignant areas and in all specimens of MLEL (14/14), PCR demonstrated a DNA fragment of 123 kbp in 2 cases of BLEL-FMT and 12 cases of MLEL (12/14). In contrast, there were no significant ISH/PCR signals in examined BLEL and nonspecific chronic sialadenitis.

CONCLUSIONSA few cases of MLEL may arise from BLEL and EBV may plays an important role in the pathogenesis of BLEL-FMT of salivary glands.