Pemphigus vulgaris of skin: cytological findings and pitfalls.

BACKGROUND

Pemphigus vulgaris (PV) is an autoimmune bullous lesion of the skin and mucous membranes characterized by suprabasal clefting and acantholysis. The responsible autoantibody is desmoglein 3, a protein constituent of the desmosome. The diagnosis of PV is based on histological examination and immunofluorescence study. In addition, cytological smears could also be informative for the initial diagnosis of PV.

CASES: Fifteen patients, 7 men and 8 women, with skin bullous disease clinically suspected of being PV were selected for cytological study. The bullae were ruptured and two smears were prepared from the fluid and stained with the Wright-Giemsa and Papanicolaou methods. The smears were taken from both new and old bullae. They showed acantholytic cells (Tzanck cells), some with amoeboid-like cytoplasmic projections, eosinophils, basophils, various forms of typical and atypical lymphocytes with irregular nuclear borders and cerebriform nuclei and dysplastic acantholytic cells with a high nucleo-cytoplasmic ratio and prominent nucleoli. The dysplastic cells were seen only in the old bullae. Histological examination and immunofluorescence study of the lesions confirmed the diagnosis of PV.

CONCLUSION

PV can be diagnosed by cytology. Without a clinical history of PV, the presence of atypical lymphocytes and dysplastic cells may lead to a false diagnosis of malignancy.