Immunohistochemistry in the diagnosis and characterisation of neoplasms affecting the central nervous system
This work describes 5 groups of tumours seen in routine neuropathological practice in Southampton between 1980 and 1986. The clinical and light microscopic findings in a total of 44 tumours are described. A panel of monoclonal and polyclonal antibodies was used in immunohistochemical studies on each group, and this made important contributions to the diagnosis and characterisation of these tumours. Six primary central nervous system lymphomas were shown to be 5 follicle centre cell lymphomas (Kiel-classification) and 1 T-cell lymphoma. 15 lymphomas causing spinal cord compression were typed as 11 follicle centre cell lymphomas, 3 T-cell lymphomas and 1 lymphoblastic lymphoma. T-cell lymphomas appear to be more likely to be localised in the spine and to have a better prognosis. In all these tumours admixed reactive cell populations were also identified immunohistochemically. Ten primitive neuroectodermal tumours of the cerebrum were examined and immunohistochemistry assisted in their distinction from lymphoma and metastatic carcinoma. It also showed evidence of differentiation in apparently poorly differentiated parts of the tumours. Immunohistochemical studies facilitated the distinction of pleomorphic xanthoastrocytoma from a monstrocellular astrocytoma and a meningeal malignant fibrous histiocytoma. The recognition of this first entity has important prognostic implications. In 10 cerebellar haemangioblastomas a panel of antibodies was used to investigate the histogenesis of the stromal cell component of these tumours. Endothelial and stromal cells were found to be antigenically distinct and neurone specific enolase activity was found in the latter. The implications of this finding are discussed. The studies confirm the important and increasing role played by immunohistochemistry in our understanding of central nervous system neoplasia.