Chanprapaph K, Pomsoong C, Tankunakorn J, et al. - This retrospective study demonstrates that clinicopathological features are somewhat different between oral lupus erythematosus (OLE), oral lichen planus (OLP), as well as other oral lichenoid lesions (OLLs), however, a significant overlap exists. There is a diagnostic implication of the quantity and distribution pattern of CD123 immunohistochemical staining in distinguishing OLE from OLP and other OLLs.

• Total 70 patients were included; 12 had OLE, 39 had OLP, and 19 had other OLLs.

• OLE patients more commonly presented with red macules, telangiectases, and discoid plaques, while OLP patients were typified by reticulated patches.

• Histological analysis showed presence of mucosal atrophy, basal vacuolization, and perivascular infiltrate in OLE, whereas mucosal hyperplasia, hypergranulosis, and compact orthokeratosis were present in OLP specimens.

• A histologic characteristic that favored other OLLs over OLE and OLP was mucosal spongiosis.

• OLE, vs OLP, had a higher median number of total CD123+ plasmacytoid dendritic cells (PDCs) in the mucosal-submucosal junction, the superficial perivascular area, and the superficial and deep perivascular areas.

• In both OLE and OLP, significantly more numerous CD123+ PDCs were detected in all of the abovementioned areas, compared with other OLLs.