Histochemical observations of lectin-binding sites and keratin distribution in calcifying epithelioma of Malherbe.

Histochemical distribution of lectin binding sites and keratin protein was studied for epithelial components, stromal elements and giant cells in calcifying epithelioma of Malherbe as well as for normal hair follicles. The HRP (horseradish peroxidase) -conjugated lectin technique was employed; the lectins used were Con A, PNA, RCA-1, DBA, SBA, WGA and UEA-1. Immunocytochemical detection of keratin protein was made using the indirect PAP technique. Basophilic cells and shadow cells in the tumor epithelial components revealed histochemical properties similar to those of matrix cells and cortex cells in growing hair follicles, respectively. Most prominent lectin binding was observed in Con A staining. In the tumor stroma, many fibrillar elements which were distinguished as immature or mature hair were found by lectin and keratin staining. Tumor giant cells showed a stronger staining for Con A and keratin, which were enhanced following treatment with amylase. The staining intensity of lectins was usually decreased in both epithelial cells and connective tissue stroma following treatment with neuraminidase.