title: Use of the silver nucleolar organizer region (AgNOR) technique in the differential diagnosis of central nervous system neoplasia.
abstract: Because the distinction between gliosis and low-grade astrocytoma may prove difficult by routine light microscopy, we evaluated the silver nucleolar organizer region (AgNOR) technique in making this distinction. The AgNOR impregnation was performed on formalin-fixed, paraffin-embedded tissue from 49 central nervous system (CNS) biopsies: eight normal brain, 14 gliosis, 14 grade 2 astrocytoma (Daumas-Duport scale), two grade 4 astrocytoma, nine medulloblastoma, one metastatic carcinoma, and one choroid plexus papilloma. Quantitative and qualitative differences were found between gliosis and low-grade astrocytomas. In gliosis, AgNOR counts averaged 1.18 +/- 0.11 (SD) AgNOR/nucleus, while in low-grade astrocytomas AgNOR counts averaged 2.22 +/- 0.39 (p less than 0.001). Compound AgNOR were frequent in 9/14 grade 2 astrocytomas and in both grade 4 astrocytomas, whereas compound AgNOR were extremely rare in cases of gliosis. Quantitative and qualitative differences were also found between normal cerebellar internal granular cells and medulloblastoma cells. Cerebellar granular cells averaged 0.90 +/- 0.10 AgNOR/nucleus whereas medulloblastoma cells had an average of 4.52 +/- 0.95 (p less than 0.001). Compound AgNOR were seen in all medulloblastomas but not in internal granular cells. These findings suggest that the AgNOR technique may be a useful adjunct in the diagnosis of CNS neoplasia.
authors.affiliation: C. S. Kubik Laboratory for Neuropathology, Department of Pathology, Massachusetts General Hospital, Boston 02114.
authors.forename: D N
authors.initials: DN
authors.lastname: Louis
authors.forename: S M
authors.initials: SM
authors.lastname: Meehan
authors.forename: R J
authors.initials: RJ
authors.lastname: Ferrante
authors.forename: E T
authors.initials: ET
authors.lastname: Hedley-Whyte
mesh_terms: D001254:Astrocytoma / Q000473:pathology; D001932:Brain Neoplasms / Q000473:pathology*; D003937:Diagnosis, Differential; D005911:Gliosis / Q000473:pathology; D006801:Humans; D008527:Medulloblastoma / Q000473:pathology; D009697:Nucleolus Organizer Region / Q000473:pathology*; D015203:Reproducibility of Results; D016622:Silver Staining