A determination of the range of oral conditions submitted for microscopic and direct immunofluorescence analysis.

BACKGROUND: Direct immunofluorescence (DIF) testing is a useful adjunct for the diagnosis of immune-mediated oral vesiculobullous diseases, helping to identify separate, histologically similar, but prognostically different, conditions. It is unknown how often biopsy of these lesions yields positive DIF results. METHODS: A total of 270 consecutive archival cases submitted to a reference laboratory in Buffalo, New York, over a 2-year span were examined. These specimens were submitted to establish or rule out a diagnosis of a DIF-positive oral vesiculobullous disease. Demographic, clinical, and diagnostic information, based on conventional microscopic and DIF analysis, was tabulated. To assess the contribution of DIF to successful diagnosis, three pathologists examined the hematoxylin and eosin-stained slides of the known DIF-positive specimens without knowledge of the DIF results. RESULTS: Approximately 48% of the specimens demonstrated positive DIF findings and consisted of pemphigus vulgaris, mucous membrane pemphigoid, lichen planus, linear immunoglobulin A disease, and chronic ulcerative stomatitis. The remaining specimens had negative DIF findings and consisted of numerous non-specific inflammatory conditions. Of particular interest were several cases of epithelial dysplasia and squamous cell carcinoma. Of the DIF-positive cases, only pemphigus vulgaris could be diagnosed reliably by conventional microscopy alone. CONCLUSIONS: Approximately half of biopsies of oral conditions that clinically resembled typically DIF-positive vesiculobullous diseases did not yield positive findings on DIF testing. Instead, a wide range of oral diseases can mimic these lesions clinically. With the exception of pemphigus vulgaris, DIF is essential for establishing a definitive diagnosis for known DIF-positive diseases.