Proliferating cell nuclear antigen in the determination of growth rates in acoustic neuromas

The growth rate of acoustic neuromas is difficult to predict clinically; however, the ability to do so would be of benefit to the clinician for patient prognostication. Laboratory studies utilizing flow cytometry and immunologic methods have been used to investigate growth rates of acoustic neuromas. The purpose of this pilot immunohistochemical study, using proliferating cell unclear antigen (PCNA) on 22 randomly selected vestibular schwannomas, was to compare the growth factors, determined immunohistochemically, with the growth rate in this class of lesions. Proliferating cell nuclear antigen is an antibody against DNA polymerase delta, which is expressed in late G1 through S phase of the cell cycle. The advantage of using PCNA is that standard archival formalin-fixed, paraffin-embedded tissues may be analyzed and that PCNA detect cells in G1 through S phase, allowing S-phase fractions, determined by flow cytometry. Results indicate that PCNA immunohistochemical analysis may potentially offer prognostic information relating to the growth potential of each tumor for individual patients with vestibular schwannomas. Further study with an expanded patient population is planned