Cytological Smear and Cell Block Versus Tissue Biopsies in the Diagnosis of Malignant Tumours in Non-Gynaecologic Specimens

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.