AGNORS IN LUNG-CANCER - CORRELATION WITH DNA-PLOIDY AND DEGREE OF DIFFERENTIATION

OBJECTIVE: To assess the usefulness of enumerating argyrophilic nucleo lar organizer regions (AgNORs) in assisting with the diagnosis, as wel l as its correlation with the degree of differentiation and DNA ploidy , in lung cancer. STUDY DESIGN: The specimens, taken from 151 benign a nd malignant pulmonary tumors, were stained with silver nitrate before the number of AgNORs was counted. DNA ploidy was determined in 58 cas es of lung cancers. All cases of adenocarcinoma and squamous cell carc inoma were histologically classified as well, moderately or poorly dif ferentiated. RESULTS: Lung cancers had more AgNORs than benign tumors, and small cell carcinomas had fewer AgNORs than non-NSCLC (P<.001). T he mean AgNOR number in adenocarcinoma increased progressively in acco rdance with poorer differentiation (P<.001). There plas no correlation between the number of AgNORs and DNA ploidy.CONCLUSION: Counting AgNO Rs helps with the differential diagnosis of lung cancers. In adenocarc inoma of the lung, the AgNOR number increases as the degree of differe ntiation decreases.