Abstract
Purpose: :
Recent Studies indicate that bcl–2 protein is detected in benign and malignant melanocytic neoplasms of the skin in addition to follicular lymphomas. To our knowledge, there are no published reports of bcl–2 studies in melanocytic lesions of the conjunctiva. The objective of our study is to evaluate bcl–2 expression in 29 conjunctival melanocytic lesions and compare the results with other immunohistochemical markers.
Methods: :
We studied biopsy specimens of 29 patients with conjunctival melanocytic lesions, including 20 nevi, 8 malignant melanomas, 3 primary acquired melanosis (PAM) and 3 malignant melanomas arisen in PAM. Immunohistochemical studies with Bcl–2, S–100, HMB45 and Melan A were performed in all cases except for 2 lesions, where Melan A was not available. Immunoreactivity was graded as weak, moderate and strong, and the pattern of staining was recorded as focal or diffuse.
Results: :
Bcl–2 showed diffuse staining in all 29 cases. The staining was strong in 25 / 29 cases (86.2%) and moderate in 4/29 lesions (13.8%). HMB45 revealed diffuse staining pattern in 8/29 (27.6%) cases, focal in 20/29 (69.0%) and negative in a single case. Staining was strong in10/29 (34.5%) cases, moderate in 6/29 (20.7%), weak in 12/29 (41.4%) and negative in one case (3.4%).
S100 protein showed diffuse expression in 20/29 cases (67.0%), and focal in 9/29 (31.0%). The reactivity was strong in 17/29 (58.6%), moderate in 5/29 (17.2%) and weak in 7/29 (24.1%).
Melan A immunoreactivity was diffuse in 22/27 (81.5%) cases and focal in 5/27 cases (18.5%). The staining was strong in 16/27(59.3%), moderate in11/27 (40.7%) and weak in 0/27(0.00%).
Conclusions: :
Our results indicate that bcl–2 expression is diffuse in both benign and malignant melanocytic lesions, with strong reactivity in most cases. Furthermore, bcl–2 expression is more consistent and stronger than S100, HMB45 and Melan A. Additional cases are needed to confirm the finding of this report.
Keywords: conjunctiva • melanoma • immunohistochemistry