Abstract
Purpose::
To study the inflammatory infiltrates associated with melanocytic lesions of conjunctiva and to investigate whether there is difference among different categories of benign nevi (BN), atypical nevi (AN) and malignant melanomas (MM).
Methods::
The inflammatory infiltrates in 8 cases of conjunctival BN, 8 cases of AN, and 9 cases of MM were studied by immunohistochmistry. The immunohistochmical markers included CD3, CD4, CD8, CD56, CD45, CD20, and CD68. The number of immunohistochemically stained lymphocytes were counted in all cases and the average number per high power field was recorded.
Results::
Most of the inflammatory infiltrates were composed of lymphocytes; however, a few plasma cells, eosinophils, histiocytes and mast cells were also observed. Lymphoid follicles were often seen in AN, which showed increased CD3 (+), CD20 (+), and CD45 (+) lymphocytes. Eosinophils were commonly seen in AN in young patients. CD3 (+) T lymphocytes were more common than in CD20 (+) B lymphocytes in BN, AN, and MM. CD3 (+) B lymphocytes were present in clumps in MM, but were scattered in BN and AN.
Conclusions::
The presence of increased CD3 (+), CD20 (+) and CD45 (+) in AN were related to the frequent presence of lymphoid follicles. Increased numbers of eosinophils in young patient may be related to an associated allergic condition. In addition, the characteristic clumping of CD3 (+) B lymphocytes only in MM was an unexpected result. These interesting findings support the need for a larger study to confirm the significance of these observations.
Keywords: conjunctiva • melanoma • immunohistochemistry