USE OF AgNOR INDEX IN GRADING AND DIFFERENTIAL DIAGNOSIS OF ASTROCYTIC LESIONS OF BRAIN

Objective: This study was conducted to see the importance of AgNOR staining in grading and differential diagnosis of Astrocytic lesions. Methodology: It was a descriptive and prospective study conducted in Department of Pathology King Edward Medical University, from June-December 2002. AgNOR staining was performed on 60 randomly selected brain specimens of Astrocytic lesions including Astrogliosis and Astrocytoma. Results: AgNOR count, size and dispersion were normal in Astrogliosis, low in Pilocytic Astrocytoma, high in grade II, higher in grade III and highest in grade IV. AgNOR counts of different grades of astrocytoma (2.97±0.96, 3.97±0.43, 6.01±2.74 and 8.01±3.56) were significantly (P< 0.01) greater as compared with counts of normal brain (0.40±0.01), and reactive gliosis (0.60±0.01). There was no statistical difference in normal brain tissues and inflammatory lesions of the brain. AgNOR size and dispersion were of higher grade in significantly greater proportion in malignancy as compared to benign conditions. (P <0.05). AgNOR size and dispersion were normal in Astrogliosis. Conclusions: Typing of AgNOR count, size and dispersion was found to be an important marker in grading and differential diagnosis of Astrocytic lesions, especially in Astrogliosis and low grade Astrocytoma.