Invasiveness in in vitro and clinical evaluation of meningiomas.

Fragments of freshly isolated human meningiomas were cultured in vitro to form cell monolayers. These monolayers were confronted with embryonic chick heart fragments in vitro for 1, 2, 4, and 7 days. Microscopically, three different histological patterns were observed. Type I included necrotized meningial cells; type II presented surviving meningial cells; type III included meningial cells that had invaded the host tissue. The clinical analysis included the histopathological diagnosis, the macroscopic situation at surgical intervention, and the follow-up with or without recurrence. Correlation between these clinical parameters and the in vitro results demonstrated that type III confrontations correlated with macroscopic infiltration in the brain parenchyma and tumor recurrence. Invasiveness in vitro was seen in two anaplastic and two transitional meningiomas.