Figure 1.

LAMP-1 immunohistochemical expression in astrocytomas. The expression of LAMP-1 was investigated immunohistochemically in diffuse and anaplastic astrocytomas as well as in glioblastomas. The expression in diffuse astrocytomas was primarily found in cells with microglial morphology (A), in blood vessels (B) and in cells with gemistocytic morphology (C). In the anaplastic astrocytomas, cells with a gemistocytic morphology also showed expression of LAMP-1 with both low (D) and high (E) expression levels. Positive cells with other morphologies were also found (F). In glioblastomas the majority of the tumors showed high expression of LAMP-1 in the tumor cells, but also tumors with large negative areas were found. In these areas the highest LAMP-1 expression was found in the blood vessels (G). LAMP-1 expression was found in tumor cells with different morphologies with different degrees of pleomorphism. Both gemistocytic (H) tumor cells as well as multinucleated giant cells (I) were found. Besides being found in tumor cells, LAMP-1 expression was also found in blood vessels (J) and in and around necrotic palisades (K, L). Scalebar A-L 100 μm, inserts 20 μm.