Topochemical demonstration of zinc in meningiomas.

In agreement with the atomic absorption tests, histochemical demonstration of zinc in meningiomas using the dithizone method revealed a higher level of zinc in fibromatous meningiomas than in its meningiotheliomatous variant. Calcified psammoma bodies and vessels exhibited an intensely positive reaction on their surface. The metabolic function of zinc in the synthesis of fibre proteins, as well as in metallo-enzymes associated with mineralization, explains these findings.