Progestin and oestrogen receptors in meningiomas. Biochemical characterization, clinical and pathological correlations in 42 cases.

Progestin receptors (PR) were evaluated in 40 intracranial and 2 spinal meningiomas. PR measured with radiolabelled R 5020 were found in 93% of cases (39/42). PR levels were significantly higher (p = 0.05) in females (mean: 5,720 fmol/gmT) than in males (mean: 3,120 fmol/gmT). Biochemical characterization of the R 5020 saturable binding sites showed that they were mainly cytosolic, had a high affinity constant (Kd approximately equal to 1 nM) and were progestin specific. Correlation with sex suggested some biological activity of PR in meningiomas. Oestrogen receptors (OR) were evaluated in 36 intracranial and 2 spinal meningiomas. OR measured with radiolabelled R 2858 were present in 79% of cases (30/38). OR mean levels were equal in females (mean: 285 fmol/gmT) and in males (mean: 330 fmol/gmT). The relevance of PR and possibly OR in the biology of meningiomas and of leptomeninges was suggested by the presence of receptors in a sample of normal leptomeninges.