LECTIN HISTOCHEMISTRY OF HUMAN MENINGIOMAS

The lectins Peanut agglutinin (PNA), Canavalia ensiformis (Con A), Ule x europaeus-1 (UEA-1), Dolichos biflorus (DBA), Triticum vulgaris (WGA ) were studied in a series of 36 meningiomas (16 meningotheliomatous-i ncluding 3 recurrences, 7 transitional, 4 angiomatous, 2 <<hemangioper icytic>>, 3 papillary-including 1 recurrence, 4 anaplastic-including 3 recurrences. PNA binds to all cases of meningotheliomatous, transitio nal, papillary and anaplastic meningiomas (including recurrent cases) but the staining is more intense in tumor cells of anaplastic and papi llary type. A semiquantitative study showed differences of PNA-reactiv ity in the different subtypes of meningiomas. In meningotheliomatous m eningiomas PNA-positivity was encountered in numerous neoplastic cells (50%), whereas papillary and anaplastic subtypes expressed strong cyt oplasmic staining of few tumor cells (< 5%). Con A shows the same patt ern of reactivity described for PNA, but more weakly. Our results sugg est that PNA is a marker of differentiation in meningiomas rather than malignant transformation and can have prognostic relevance.