Evaluation of elastic fibers pattern with orcein staining in differential diagnosis of lichen planopilaris and discoid lupus erythematosus.

Differential diagnosis of lichen planopilaris and discoid lupus erythematosus especially in late stages is a problem for clinicians and pathologists. Our aim was to find discriminator histopathologic findings that help us to achieve definite diagnosis without using immunofluorescence study. The histopathologic findings in 77 cases of lichen planopilaris were compared with those of 26 cases of discoid lupus erythematosus with Hematoxylin & Eosin and especially staining (Alcian blue pH 2.5, Periodic Acid Shiff, Orcein). Final histopathologic diagnosis was based on histologic findings, clinicopathological correlation, past medical history and immunofluorescence studies if were applied before. Then elastic fibers pattern in dermis and follicular sheath with orcein staining were described without having information about final diagnosis. New and subtle presentations of histologic changes were assessed. We compared all histopathologic finding for each staining method. Some histologic changes such as hypergranulosis, epidermal atrophy, mucin deposition, diffuse scar and some other patterns were not specific for any diagnosis. A setting of histopathologic findings and clinicopathological correlation were needed for accurate diagnosis. We had only one specimen for the vertical section, and we had no horizontal sections. Description of elastic fibers pattern in orcein staining may be helpful in achieving a specific diagnosis, but this is not completely reliable, and we had overlap features. Finally, immunofluorescence study may be recommended for suspicious cases.