Calcifying epithelioma of Malherbe with ossification. Special reference to lectin binding and immunohistochemistry of ossified sites.

Lectin binding sites and immunohistochemically detectable fibronectin and carbonic anhydrase II (CA II) were examined in induced bone structure of calcifying epithelioma of Malherbe. Pathological features of ossification were particularly evident in the border zone between tumor epithelium and stroma, and epithelial foci adjacent to sites of bone formation were conspicuously basophilic. The use of lectin binding in these foci coincided with the basophilic epithelial zones: Con A, RCA-1, PNA, SBA, and WGA bound strongly, indicating the presence of glucose (Glu), mannose (Man), galactose (Gal), N-acetyl-D-galactosamine (GalNAC), and N-acetyl-D-glucosamine (GlcNAC). Fibronectin was also detected in the same epithelial-mesenchymal interacting layers as the positive lectin-binding sites. Staining for CA II was strongly positive in giant cells and in epithelial zones in the bone-inducing areas. The bond induction mechanism in the stromal tissue of calcifying epithelioma of Malherbe may initially involve the action CA II in the epithelial-mesenchymal interacting zone, which then brings about ossification of the matrix which is fibronectin-positive and rich in lectin-binding sites.