Qligodendrogliomas: a clinical, histological, immunocytochemical and lectin-binding study

We have studied 27 oligodendrogliomas with a panel of antibodies (vimentin, GFAP, S-100 protein, myelin basic protein, CAM 5.2) and of lectins (WGA, Con A, PNA, RCA, DBA, SBA) to different glycoproteins. There were 16 well-differentiated tumours, including one gliofibrillary and 11 anaplastic oligodendrogliomas, three of which were gliofibrillary. Four cases showed positivity for vimentin, three of which were anaplastic tumours. Fifteen cases were positive for S-100 protein (nine well-differentiated and six anaplastic tumours) and 13 contained GFAP-positive cells (three well-differentiated and 10 anaplastic tumours). WGA binding was positive in 75% of well-differentiated and 63% of anaplastic oligodendrogliomas, the corresponding figures were 50% and 45% for PNA, 37% and 81% for Con-A and 25% and 54% for RCA. On the basis of the results with lectin binding, we believe that there are changes in the spectrum of tumour cell-associated lectin-like proteins during malignant transformation. Our observations also suggest that the pattern of lectin expression can undergo substantial changes in the course of differentiation.