The Copper and Zinc-superoxide Dismutase Expression in Human Acoustic Schwannomas : An Immunohistochemical Study

Abstract

Using a immunohistochemical technique, the sites of the copper and zinc-superoxide dismutase (Cu, Zn-SOD) expression has been examined in acoustic schwannomas. These acoustic schwannomas included three cases associated with Recklinghausen disease (R-AS) and seven cases without von Recklinghausen disease (N-AS). Histologically, two out of four R-AS schwannomas were Antoni's type A, one was Antoni's type B, and one was a mixed type. The N-AS cases demonstrated four Antoni's type A schwannomas, two that were a mixed type, and one Antoni's type B schwannoma. The Cu, Zn-SOD expression was localized diffusely in the cytoplasms of the tumor cells of both the Antoni's type A and type B schwannomas. Occasionally, immunoreactive Cu, Zn-SOD products were revealed in the cytoplasms of the endothelial cells, the neutrophils, the macrophages, and the cell membranes of the erythrocytes. The percentage of the Cu, Zn-SOD content in the tumor cells ranged from 31〜63% in the R-AS cases, and from 43〜58% in the N-AS cases, and from 37〜66% in the Antoni's type A schwannomas of the R-AS cases, and 31% in the type B schwannomas. The Antoni's type A schwannomas of the N-AS cases showed a Cu, Zn-SOD positivity that ranged from 47〜60%, whereas the type B schwannomas showed a positivity that ranged from 43〜58%. Thus, no significant difference was noted in the SOD content among the Antoni's type A, type B, and mixed type schwannomas. However, a tendency towards a higher SOD content was recognized in Antoni's type A rather than in type B schwannomas.