[Distribution of silver staining-nucleolar organizer regions (Ag-NOR) in nasopharyngeal carcinoma]

Using silver staining technique, nucleolar organizer regions (Ag-NOR) were studied in paraffin section of 20 nasopharyngeal carcinoma (NPC), 10 chronic nasopharyngitis and 10 benign hyperplasia of mucosal epithelial. The results suggested that Ag-NOR showed clear black dots in nuclei. Malignancy lesion possessed much more Ag-NOR per nucleus than the other benign. In NPC a mean value of 5.95 (s1.78) Ag-NOR per nucleus was found, chronic nasopharyngitis was 1.31 (s0.14) and benign hyperplasia of mucosal epithelial was 2.16 (s0.34). This content of Ag-NOR per nucleus has a distinct difference in between NPC and benign lesion. We thought that the Ag-NOR technique would have an important value for differential diagnosis of benign and malignancy in nasopharyngeal lesion.