Purchase this article with an account.
KM Oliver, GS Lima, AL Caissie, J-CA Marshall, J Deschenes, MN Burnier; Cyclooxygenase-2 (COX-2) Expression in Primary Acquired Melanosis . Invest. Ophthalmol. Vis. Sci. 2002;43(13):1105.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Purpose: Primary acquired melanosis (PAM) is a unilateral melanocytic conjunctival lesion. PAM begins as a melanocytic proliferation of small polyhedral shaped cells with no atypia and, if left untreated, may progress to PAM with atypia, ranging from mild to severe (epithelioid cells) forms. Approximately forty percent of PAMs with atypia undergo malignant transformation to conjunctival melanoma. The expression of the prostaglandin synthetase COX-2 has been investigated in many human malignancies such as skin and uveal melanoma as well as colon cancer, in which the administration of COX-2 inhibitors to patients with familial adenomatous polyposis has been shown to prevent the malignant transformation of pre-cancerous polyps. The objective of this study is to investigate the expression of COX-2 in the early stages of PAM and correlate the findings with the presence or absence of cytological atypia in the lesions. Methods: Fourteen cases with a clinical and pathological diagnosis of PAM were studied. The formalin-fixed, parrafin-embedded specimens of PAM were retrieved from the Henry C. Witelson Eye Pathology Laboratory, Montreal, Canada. Slides were reviewed for the presence of atypia. The specimens were immunostained with a monoclonal antibody against COX-2 and the intensity of the COX-2 expression was recorded as 0, +, or ++. Results: Histopathologically, four out of 14 cases of PAM showed mild atypia and the other 10 cases showed no atypia. All 14 cases of PAM were negative for COX-2 expression. Conclusion: In this study, all cases of primary acquired melanosis were COX-2 negative regardless of the presence or absence of atypia. COX-2 expression could not be linked to the early stages of primary acquired melanosis progression. It is not known whether COX-2 expression may play a role in the more severe forms of primary acquired melanosis with atypia, or the malignant transformation to melanoma, therefore, further studies investigating COX-2 expression in conjunctival melanoma as well as PAM with severe atypia, should be performed.
This PDF is available to Subscribers Only