Scrape cytology of oral pemphigus: Report of a case with immunocytochemistry and light, scanning electron and transmission electron microscopy

BACKGROUND: Pemphigus vulgaris is a disseminated disease of the skin and mucous membranes characterized by recurrent vesicular and bullous lesions due to the autoantigen belonging to the cadherin type of cell adhesion molecules. The presence acantholysis associated with immunoglobulins in the intercellular spaces and on the cell membrane are diagnostic features. However, the appearance of smears from the oral cavity by scanning (SEM) and transmission electron microscopic (TEM) study as well as immunocytochemistry of cadherin does not appear to have been previously reported. CASE: A 67- year-old female developed erosion on her gingiva with severe pain. On oral examination, there were ulcerations on the palate, and the Nikolsky sign was positive. The characteristic cytologic findings from oral scrapes were high cellularity, a bloody background and a predominant cell population consisting of polygonal basal and parabasal cells with pronounced nucleoli. Also present were degenerative cell changes: e.g., cytoplasmic vacuoles and a homogeneous nuclear appearance. Immunocytochemical staining for IgG and cadherin gave a positive reaction in the intercellular spaces and on the cell membranes. The surface of cells in pemphigus vulgaris by SEM showed somewhat irregularly distributed microridges, and TEM revealed desmosomal attachments, degenerated tonofilaments with pronounced nucleoli and heterochromatin. As a result of cytodiagnosis, additional appropriate specimens were obtained at the time of the scraping for confirmatory immunocytochemistry for cadherin, SEM and TEM studies. CONCLUSION: The results demonstrate that a precise diagnosis of pemphigus vulgaris can be rendered on cellular material and cadherin immunocytochemistry obtained by scrape from the oral mucosa.