title: Growth of vestibular schwannomas: in situ model employing the monoclonal antibody Ki-67 and DNA flow cytometry.
abstract: Vestibular schwannoma (VS) growth potentials were studied in an in situ model, in which the cycling cellular fraction was determined immunohistochemically by applying the mouse monoclonal Ki-67 antibody, and the tumor ploidy was estimated by DNA flow cytometry in a consecutive series of 124 VSs. The tumors were classified according to the average number of positively stained nuclei in 10 high-power fields into three groups: 28 highly (> 10), 33 moderately (> 5-10) and 63 low proliferating (< or = 5). The intratumoral proliferative variation was studied in 10 tumors. Only slight variation in the number of the positively stained nuclei were observed. Six of seven tumors removed because of macroscopically documented growth by computed tomography (CAT) scan were moderately or highly proliferative. Proliferation of VS was correlated to prospectively registered clinical data. A statistically significant relation was found between VS proliferation and the prediagnostic duration of symptoms (p = 0.0001). The proliferative status was unrelated to age, sex, and tumor size. Flow-cytometric determination of DNA index of the 124 tumors revealed 12 tetraploid (DNA index = 2), 110 diploid (DNA) index = 1) and two nondiploid tumors. A statistically significant relation was noted between tumor ploidy and proliferation status expressed by Ki-67 (p = 0.024). The tetraploid tumors showed significantly lower proliferation compared with the diploid tumors. Tumor ploidy was statistically unrelated to age, sex, tumor size, and duration of symptoms. The results of this study provide a link between the immunohistochemical, flow cytometric findings, and clinical data, which could probably be relevant in identifying patients at risk for rapid tumor growth and tumor recurrences, because a rapid test for cell proliferation is now available.
authors.affiliation: Department of Otorhinolaryngology, Head and Neck Surgery, Gentofte University Hospital, Hellerup, Denmark.
authors.forename: S
authors.initials: S
authors.lastname: Charabi
authors.forename: P
authors.initials: P
authors.lastname: Engel
authors.forename: B
authors.initials: B
authors.lastname: Charabi
authors.forename: G K
authors.initials: GK
authors.lastname: Jacobsen
authors.forename: J
authors.initials: J
authors.lastname: Overgaard
authors.forename: J
authors.initials: J
authors.lastname: Thomsen
authors.forename: M
authors.initials: M
authors.lastname: Tos
mesh_terms: D000328:Adult; D000368:Aged; D000911:Antibodies, Monoclonal; D002465:Cell Movement; D004247:DNA; D004171:Diploidy; D004428:Ear Neoplasms / Q000175:diagnosis* / Q000473:pathology*; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D009442:Neurilemmoma / Q000175:diagnosis* / Q000473:pathology*; D011446:Prospective Studies; D014722:Vestibule, Labyrinth / Q000473:pathology*
chemical_list: D000911:Antibodies, Monoclonal; D004247:DNA