Cytology of angiosarcoma in effusions.

The cytologic and immunocytochemical findings in pleural effusions from three cases of angiosarcoma are presented. In two of the cases, the primary lesion was on the scalp; in the third case, an angiosarcoma of the small intestine developed after radiotherapy for Hodgkin's disease. Single malignant cells and small clusters of cells were seen in cytologic preparations from two cases while only single cells were seen in preparations from one case. The malignant cells had delicate, finely vacuolated cytoplasm with distinct borders. No specific morphologic features were noted. Immunoperoxidase studies revealed binding of Ulex europaeus and reactivity for vimentin in all three cases and expression of Factor VIII-related protein in two of the cases but no expression of epithelial markers. The clinical history and immunoperoxidase studies are necessary to distinguish angiosarcoma from metastatic adenocarcinoma and other malignancies in effusions.