USEFULNESS OF ARGYROPHILIC NUCLEOLAR ORGANIZER REGIONS SCORE TO DIFFERENTIATE SUSPICIOUS MALIGNANCY IN PULMONARY CYTOLOGY

Objective: Pulmonary cytologic specimens reported as ''suspicious for malignancy'' pose problems in clinical management, Silver staining for argyrophilic nucleolar organizer regions (AgNOR) has proved useful in making a cytopathologically differential diagnosis between benign and malignant cells, This study aimed to evaluate the usefulness of AgNOR score in the diagnosis of pulmonary cytologic specimens deemed inconc lusive by conventional staining methods, Methods: Pulmonary cytologic specimens initially reported as suspicious for malignancy with Papanic olaou or May-Grunwald-Giemsa (MGG) staining obtained from 35 proved ca ses were destained then restained using the AgNOR technique, Another 3 5 cases with clear cytologic diagnosis were also examined for comparis on. The median number of dots, defined as the AgNOR score, mas used to differentiate malignant from benign specimens. Results: Malignant cas es had significantly higher AgNOR scores than benign ones (p < 0.001), There were no significant differences among smears previously stained with Papanicolaou or MGG method, among specimens obtained via broncho scopic brushing, fine-needle aspiration of lung or pleural effusion, o r among subgroups of malignant diseases. Based on the results of our p revious study, the cutoff value of the AgNOR score to differentiate be nignancy from malignancy was set at 6. At this setting, the sensitivit y and specificity of AgNOR store were 88% and 80%, respectively, in ai ding a differential diagnosis of pulmonary cytologic specimens initial ly classified as suspicious for malignancy. For those cases with a cle ar cytologic diagnosis, the sensitivity and specificity of AgNOR score were 92% and 100%, respectively. For all cases, the sensitivity of Ag NOR score was 90% and the specificity was also 90%. Conclusions: The A gNOR score is of value in aiding a differential diagnosis between beni gn and malignant lesions in pulmonary specimens with equivocal cytolog ic features.