Evaluation of Proliferative Marker Ki-67 in Adenoid Cystic Carcinoma: A Retrospective Study.

Aim: Adenoid cystic carcinoma (ACC) is a malignant tumor of salivary gland origin. Although the histologic appearance of ACC is low grade, management of this malignancy is a distinct therapeutic challenge because of its tendency for perineural involvement and potential for distant metastasis. Ki-67 antigen is expressed during the G1, S, G2 and M phases in the cell cycle but is absent in the quiescent G0 phase in tissue sections.