Figure 1.

Histological aspects of representative cases: (a) obstruction of a salivary gland excretory duct due to a calcified calculus. The periductal inflammation can be noted (haematoxylin and eosin, original magnification × 150). (b) Chronic sialadenitis in a case of lupus erythematous (haematoxylin and eosin, original magnification × 200). (c, d) Pleomorphic adenoma of the parotid gland: in (c), a nodular neoplasm surrounded by a fibrous pseudocapsule can be noted. In (d), the neoplasm is composed of spindle myoepithelial cells, ductal structures and a myxoid amorphous material (haematoxylin and eosin, original magnification × 40 and × 400, respectively).