[Ultrastructural and histochemical study of a pleomorphic adenoma of the palate]

Histochemical and ultrastructural study of the epithelial regions forming lumina in one case of pleomorphic adenoma of the palate was undertaken. The ultrastructural findings suggest that these epithelial regions are derived from the intercalated ducts. The presence in the cytoplasm of periluminal cells of pinocytotic vesicles and vacuoles containing material similar in appearance of that seen in the luminal supports a reabsorptive activity of these cells. The microcalculi of calcium phosphate occasionally seen in the cytoplasm of these cells may be formed by the phagocytosis of the endocytotic material from the lumina.