USEFULNESS OF AGNOR SCORE IN DIFFERENTIATING BENIGN FROM MALIGNANT PULMONARY ASPIRATION CYTOLOGY

OBJECTIVE: Malignant cells are known to display greater argyrophil sta ining for nucleolar organizer regions (AgNORs) than for benign cells d ue to their active proliferation. In this study we assessed the diagno stic value of AgNOR staining on 47 fine needle aspiration cytologic sp ecimens of lung previously stained with the May-Grunwald-Giemsa (MGG) method. METHODS: Cytologic specimens obtained from fine needle aspirat ion of the lung in 47 proven cases prestained with the MGG technique w ere destained and restained with the AgNOR method. Seventeen of them w ere benign and 30 malignant. To differentiate malignant from benign en tities, the highest median value for AgNOR number (AgNOR score) obtain ed from the benign cases was chosen as a cutoff point (test specificit y, 100%). RESULTS: AgNOR scores of malignant cases were significantly higher than those of benign cases (P < .001). There was no significant difference between two subgroups of benign diseases or among four sub groups of malignant diseases. The sensitivity of the AgNOR score tons 93% (28/30) in providing a diagnosis of malignancy when the cutoff val ue was set at 6. CONCLUSION: The AgNOR technique may be of considerabl e value in aiding a diagnosis of malignancy, especially when the score is >6.