Expression of CD30 and nerve growth factor-receptor in neoplastic and reactive vascular lesions: an immunohistochemical study. 
A total of 118 biopsies from 20 different types of benign, malignant and reactive vascular proliferations were examined for the expression of the CD30 antigen using the monoclonal antibodies BerH2 and HRS4 on paraffin-embedded sections.  The results were compared with those obtained using an antibody directed against the partially homologous nerve growth factor-receptor.  The vascular character of the lesions was assessed by means of endothelial markers and the expression of intermediate filaments was verified immunohistochemically.  CD30 was expressed in the endothelial component of more than the half of all tumours, with the exceptions of Kaposi's sarcoma and teleangiectatic granuloma.  There was a slightly higher rate of Ki-1 positivity in malignant lesions.  Nerve growth factor-receptor could be demonstrated in a similar percentage in both endothelium and pericytes, but no correlation with CD30 could be established.  We conclude, therefore, that these antigens are not adequate for the differential diagnosis of vascular lesions, nor do they help distinguish between benign and malignant lesions.  Their expression seems to reflect different states of cellular function or activation.  It does not necessarily occur simultaneously or in the same cell type.