p53 Immunostaining in benign and malignant effusions

ABSTRACT

To evaluate p53 immunostaining as a marker of malignancy in pleural and peritoneal effusions and to compare the results with HE staining. Design: Pleural and peritoneal effusion samples were obtained from patients suffering from benign and malignant diseases. H and E staining and p53 immunostaining were performed on smears prepared from these samples. Setting: The samples were obtained from patients admitted in Mayo Hospital, Services Hospital, Gulab Devi Chest Hospital and Institute of Nuclear Medicine and Oncology [INMOL]. Subjects: One hundred cases having either pleural or peritoneal effusions were selected. Fifty of these cases were positive for malignant cells on H and E staining. Fifty cases contained only mesothelial cells. Main outcome measures: To compare the specificity and sensitivity of p53 immunostaining with HE stain as a diagnostic marker of malignancy. Out of the 50 malignant cases, 31 [62%] were found to be p53 positive. None of the benign cases showed positive staining. p53 was found to have a specificity of 100%, sensitivity of 62%, a positive predictive value of 100% and a negative predictive value of 72.4%. Conclusions: p53 is a highly specific and moderately sensitive marker of malignancy