ABSTRACT
INTRODUCTION: There are few published studies comparing immunofluorescence on formalin-fixed, paraffin-embedded (FFPE) tissue sections (IF-P) and immunoperoxidase on FFPE tissue sections (IP-P) with immunofluorescence on frozen sections (IF-F) for evaluation of renal diseases. Also, the accuracy for each method differs greatly. The aim of this study was to evaluate IF-P and IP-P as an alternative to IF-F (gold standard method) in the diagnosis of renal biopsies specimens. METHODS: In all, 101 renal biopsies were subjected to IF-P, IP-P, and IF-F staining to demonstrate immunoglobulin IgA, IgG, and IgM immune deposits. Sensitivity, specificity, false-positive, and false-negative values were calculated. RESULTS: IP-P showed sensitivity of 61.8%, 74.2%, and 64.2%, and specificity of 84.8%, 69.2%, and 66.7% for IgA, IgG, and IgM, respectively. IF-P showed a sensitivity of 45.6%, 69.4% and 52.8%, and specificity of 87.9%, 87.2% and 77.1% for IgA, IgG and IgM, respectively. False-positive cases of IF-P and IP-P were 4, 5, and 11 and 5, 12, and 16 for IgA, IgG, and IgM, respectively. CONCLUSION: Where IF-F lacks glomeruli or fresh renal biopsies are not available, IP-P is a sensitive method, whereas IF-P is a specific method for the evaluation of immune deposits in the renal tissue biopsies. The presence of false-positive cases in both methods deserves further research.
ABSTRACT
BACKGROUND: Cytological smear and cell block (CB) are routinely used to diagnose non-gynaecologic specimens. However, there is scanty information in the literature to compare cytological smear and CB with the corresponding tissue biopsies. This study is aimed at evaluating the accuracy of cytological smear and CB in the diagnosis of malignant tumours in non-gynaecologic specimens. MATERIALS AND METHODS: A total of 70 malignant cases were subjected to cytological smear and CB. Corresponding histopathology was also included. The most frequent immunomarkers found between CB and tissue biopsies were also correlated. Accuracy, sensitivity, specificity, positive predictive value, negative predictive value, false positive and false negative values were analyzed for each method. RESULTS: The accuracy, sensitivity and positive predictive value for cytological smear were 92.8%, 100.0% and 92.9%, whereas for CB were 91.4%, 98.4% and 92.7%, respectively. In CB method, the accuracy, sensitivity and positive predictive value for CK7 were 88.9%, 91.7% and 95.6%, whereas for CK5/6 were 75%, 100% and 57.1%, respectively. CONCLUSION: Cytological smear and CB are very sensitive and accurate in the detection of malignant tumours in nongynaecologic specimens. Additional corresponding tissue biopsies should be re-evaluated.
