ABSTRACT
Differentiation of benign from malignant mesothelial proliferations is a major problem in the pathology of the serosal membranes, particularly in small biopsy specimen. This study was conducted for the evaluation of proliferative marker for distinction between malignant mesothelioma [MM] and mesothelial hyperplasia [MH]. Thirty six cases of malignant mesothelioma [MM] with the mean age of 62.94 years [range: 36-80 years, M/F: 3.58] and 22 cases of mesothelial hyperplasia [MH] were evaluated for proliferative status by immunohistochemical [IHC] method with monoclonal antibody, Ki-S5 [Ki-67]; the labeling indices [LI] were evaluated. Average count revealed a significant increase in MM as compared with reactive MH [p value < 0.0001]. Considering a threshold of 9% for ki-67, a sensitivity of 88% and specificity of 94% were resulted. Proliferative marker of Ki-67 can be useful in distinction between malignant mesothelioma and mesothelial hyperplasia [p-value < 0.0001]