Immunocytochemical characteristics of perivascular and intratumoral foam cells in neoplasms of neuroectodermal origin with lysozyme, alfa1-antitrypsin, protein S-100 and GFAP.

Investigations were performed to become acquainted with the immunohistochemical features of foam cells localized perivascular and intratumoral in neoplasms of neuroectodermal origin. Antibodies against lysozyme (muramidase) (LO), alfa 1-antitrypsin (AT), protein S-100 and glial fibrillary acid protein (GFAP) were used. A weak or medium intense reaction result has been obtained in the cytoplasm of the foam cells if antibodies against LO, and alfa 1-antitrypsin and almost negative result if antibodies against protein S-100 and GFAP were used. Only very few cells which differ from the foam cells morphologically were very intense stained with primary antibodies against LO and alfa 1-antitrypsin. In accordance with the present views the LO and AT positive cells were recognized as macrophages. The application of macrophage markers did not allow us to ascribe unequivocally the foam cells macrophage-like or histiocyte-like properties. May be that the foam cells in tumors of perivascular and intratumoral localization present another phenotypic defined group of histiocytes, despite their morphological similarity to those cells derived from smooth muscle cells of arterial blood vessels observed in arteriosclerosis.