Evaluation of AgNORs in pulmonary lesions: a cyto-histopathological correlation

Silver nucleolar organizer regions (AgNORs) were studied in one hundred specimens of endobronchial brushings. Bronchial biopsies were also obtained from these one hundred cases and subjected to AgNOR staining. These included twenty histologically normal cases, ten cases of inflammatory pathology and seventy cases of pulmonary neoplasms. Fixed cytologic smears and three micron thick sections of paraffin embedded tissue were subjected to AgNOR staining. The mean AgNOR counts in bronchial tissue showed a progressive and statistically significant increase from normal, through inflammatory to neoplastic lesions in both cytologic smears and histopathologic specimens. The AgNOR technique is simple, inexpensive and a useful adjunct to routine histopathology, to evaluate pulmonary lesions. The counts, however, cannot be standardized for a particular lesion as there are inter-laboratory variations.