Abstract
Purpose:
To evaluate the use of immunohistochemistry staining in scoring and prognostic classification of conjunctival melanocytic intra-epithelial neoplasia (C-MIN), and analyze how the diagnosis of primary acquired melanosis at Stanford University correlates with C-MIN scoring.
Methods:
A histologic review was performed of conjunctival melanocytic lesions at Stanford University Medical Center from 1990 to present with immunohistochemistry staining for Ki67/MelanA and MiTF. Lesions were evaluated using the C-MIN scoring system by hematoxylin and eosin staining alone, versus in conjunction with the aforementioned special staining.
Results:
Immunohistochemical staining enhanced the identification of pagetoid spread (5/18 cases), vertical spread (8/18 cases), and permitted objective measurement of mitotic index. In seven cases (38.9%), the addition of these studies altered the C-MIN score and in one case, the change was clinically significant. In addition, the C-MIN scores showed statistically significant correlation with the mitotic index.
Conclusions:
The use of immunohistochemical staining is helpful, and arguable necessary, for proper evaluation of conjunctival melanocytic lesions using the C-MIN scoring system, and can have clinical consequences on the management of lesions. MelanA and MiTF staining allow for more accurate identification of melanocytes, especially in terms of pagetoid spread, and Ki67 provides insight into the virulence of lesions. The incorporation of mitotic index may aid classification of these pigmented lesions.
Keywords: 588 melanocytes •
474 conjunctiva •
554 immunohistochemistry