Expression of the caveolins in dermal vascular tumors.

INTRODUCTION: Histopathologic criteria are usually sufficient for the accurate distinction of benign from malignant dermal vascular tumors. A minority of cases, however, pose a vexing diagnostic dilemma. Recent studies suggest that caveolin, a scaffolding cell membrane protein, may prove helpful in predicting the biologic behavior of endothelial-derived neoplasms.
METHODS: We analyzed a series of 30 dermal vascular tumors including 12 lobular capillary hemangiomas (LCH), 4 cases of targetoid hemosiderotic hemangiomas (TH), 4 cases of tufted angioma (TA), 12 cases of Kaposi's sarcoma (KS), 4 epithelioid (EH) and 1 spindle cell hemangioendothelioma (SH), and 4 cases of angiosarcoma (AS). The distribution of immunoreactivity was analyzed by quantifying cell membrane staining in each case.
RESULTS: There was a statistically significant difference in the expression of caveolin between LCH (mean labeling index=91.6), TH (mean labeling index=89.7), and TA (mean labeling index=87.2) and the cases of KS (mean labeling index=21.6, EH mean labeling index= 23.1), and the AS (mean labeling index=6.3).
CONCLUSIONS: These results indicate that antibodies to caveolin may be useful in separating benign and malignant dermal vascular tumors and possibly implicates this peptide in their pathogenesis.