Primary lymphomas of the central nervous system; in vitro culture observations

Out of 960 human brain neoplasms seven primary lymphomas were cultured and grown up to twenty eight days. The monolayers had common cytological characteristics; /i/ immediately after plantation a high density of uniform cells was observed; /ii/ many cells were lost during subsequent medium changes; /iii/ the monolayers contained lymphocyte-like cells in different numbers. According to their individual characteristics the cultures could be classified into three categories: 1./ In the cultures of three tumours lymphocyte-like cells predominated. These tumours had low proliferative capacity in vitro. 2./ Cultures of three other tumours consisting mainly of tissue macrophages had a high proliferative capacity in vitro. 3./ Cultures of a single tumour showed the combined features of the former two categories: both lymphocyte-like cells, and tissue macrophages were present. These cultures showed the highest proliferative activity. On the basis of these findings it is quite possible that beside other methods, tissue culture technique may be useful in the classification of brain lymphomas.