RESUMO
OBJECT: To gather information concerning ontogeny, the authors present the results of immunohistochemical stainings of neuronal and glial markers and the reverse transcriptase-prolongation chain reaction (RT-PCR) of nestin for three intraventricular tumors located around the foramen of Monro. METHODS: Seven cases of central neurocytomas(CN), three subependymomas(SE) and eight subependymal giant cell astrocytomas(SEGA), were included in this study. Antihuman monoclonal antibodies of synaptophysin(SNP)(DAKO, 1:20), chromogranin A(ChrA)(DAKO, 1:100), neuron specific enolase (NSE)(DAKO, 1:500) and nerve cell adhesion molecule(NCAM)(Zymed, 1:500) were utilized for neuronal markers and glial fibrillary acidic protein(GFAP)(DAKO, 1:300) functioned as a glial marker in immunohistochemical(IHC) stainings. Reverse transcriptase polymerase chain reaction(RT-PCR) for nestin was performed in all cases. RESULTS: For chromogranin A, positive reaction was found in three of the seven CN cases but none of the SE and SEGA cases. For IHC staining of synaptophysin, positive reaction was revealed in all CN cases but in none of the SE and SEGA cases. For NCAM, positive reaction was demonstrated in five of the eight SEGA cases and in all SE and CN cases. For NSE, positive reaction was exhibited in seven of the eight SEGA cases and in all SE and CN cases. Positive reactions for NSE and NCAM in the SEGA cases were manifested mainly in the cytoplasms of giant cells and their background. For IHC staining of GFAP, positive reaction was demonstrated in one of the seven CN cases, in three of the eight SEGA cases, and in all SE cases. RT-PCR product of nestin was expressed in two of the seven CN cases, in two of the three SE cases, and in one SEGA case. CONCLUSION: Many cells of CN, SE and SEGA, had expressed positive reactions for both neuronal and glial markers in IHC study and nestin in RT-PCR. It is suggested that origin cells of these tumors might express both neuronal and glial differentiation.