Clinical and morphological investigations on ependymomas and their tissue cultures.

A morphological investigation was carried out on 56 ependymomas cultivated in vitro as short-term cultures in roller tubes. The tumours had been histologically classified as cellular and fibrillary ependymomas, subependymomas, myxopapillary and malignant ependymomas (Table 1). A very good growth was detected in 32 cases, most of them being cellular and malignant ependymomas (Table 2). The prevailing growth pattern was epithelial in type, i.e. proliferating cells forming a carpet. In some cases, in the first stages of growth elongated bipolar cells did appear, but they evolved later as flattened epithelial elements. In four cases, a mixed proliferation of piloid astrocytes and ependymal cells was seen; these tumours were regarded as mixed gliomas. In 46 cases an exact evaluation of the history was possible. Although no correlation could be found between histology and survival time (Table 4), the longest survival was observed in spinal tumours (Table 3). Tumours in children had a slightly worse prognosis in comparison with adults (Table 5). A radical removal of the tumour was generally followed by a longer survival time (Table 6), although the operative procedure employed did not seem to influence the development of recurrences (Table 7).