Distinguishing early melanoma histochemically.

This is an interesting paper that may point the way ahead in looking at distinguishing early melanoma from Clarke's (dysplastic) nevi. It may be useful in those more severly dysplastic histopathologically. Mind you most of us excise these fully anyway. Simply trying this test with a biopsy would not be the best thing to do!(IMCC)

Cyclooxygenase-2 (COX-2): first immunohistochemical marker distinguishing early cutaneous melanomas from benign melanocytic skin tumours.

ORIGINAL ARTICLES

Melanoma Research. 17(3):139-145, June 2007.
Chwirot, Barbara W.; Kuzbicki, Lukasz
Abstract:
We have reported recently that changes in expression level of COX-2 are correlated with development and progression of human melanoma. In this study, we investigated whether the COX-2 expression level might be a useful immunohistochemical marker for distinguishing cutaneous melanomas from benign melanocytic lesions. Up to now, immunohistochemical markers have not ensured satisfactory sensitivity and specificity of differential pathologic diagnosis of melanoma. The expression of COX-2 was determined immunohistochemically in formalin-fixed, paraffin-embedded specimens of 33 early Clark I/II melanomas and 58 naevi. Mean COX-2 expression in melanomas was significantly stronger than in naevi (P[almost equal to]10-13). A simple diagnostic algorithm using threshold values of the COX-2 expression level allows for differentiation between early melanomas and naevi with high sensitivity (Se) and specificity (Sp) (for Se between 91 and 100%, Sp values change between 96.5 and 51.7%). Areas under the receiver operating characteristic curves were, respectively, 0.97+/-0.02 and 0.86+/-0.04 for the COX-2 expression in central and border regions of the lesions. For all the melanomas (not only the early ones),the respective areas under the ROC curve values were 0.98+/-0.01 and 0.97+/-0.02. In conclusion, COX-2 is the first immunohistochemical marker that allows the distinguishing of early melanomas from benign melanocytic lesions with both high sensitivity and specificity.