A COMPARATIVE-STUDY OF VASCULAR PROLIFERATION IN BRAIN METASTASIS OF LUNG CARCINOMAS

Because of the marked vascular proliferation seen in brain metastases of small cell carcinoma of the lung (SCCL), we studied the morphometri c and immunohistochemical characteristics of proliferating vessels in metastases from 20 autopsy cases of SCCL with brain metastasis. These were compared with those in surgically resected brain metastases of lu ng carcinomas, including 6 cases of SCCL, 19 cases of adenocarcinoma a nd 5 cases of squamous cell carcinoma. Angiogenesis in the tumours was scored by the microscopic angiogenesis grading system (MAGS). The MAG S score for autopsy and surgical metastatic lesions was highest in SCC L. Histologically, many vascular glomeruloid structures were formed in the brain metastases of SCCL, and immunohistochemistry revealed that these lesions were composed of proliferating endothelial cells and per icyte/smooth muscle cells. Immunostaining for basic fibroblast growth factor, a potent angiogenic factor, showed immunoreactivity in the tum our cells, regardless of histological type, and in the surrounding gli al cells. Complex autocrine and paracrine phenomena participate in the development of metastatic cerebral lesions with vascular proliferatio n.