A histopathologic study of oral mucosal lupus erythematosus.

Specimens representing 17 cases of each of oral mucosal lupus erythematosus (LE) and lichen planus were examined under the light microscope to establish a set of histopathologic criteria that would distinguish between the two. Statistical analysis showed that significant differences in histopathology exist between the two diseases. A classic case of LE was found to exhibit the following characteristics: vacuolization of keratinocytes, patchy PAS-positive deposits subepithelially, edema in the lamina propria, PAS-positive thickening of blood vessel walls, and the presence of a severe or perivascular inflammatory cell infiltrate. A number of other less significant alterations were also identified. It is concluded from this study that oral LE in most cases is characteristic enough to provide a definitive diagnosis at the light microscopic level.