Fine Needle Aspiration Cytology of the Warthin's Tumor Misinterpretated as Squamous Cell Carcinoma: A Case Report / 대한세포병리학회지

ABSTRACT

We report a case of Warthin's tumor of the parotid gland in a 53?year?old man, which is incorrectly diagnosed as squamous cell carcinoma. Fine needle aspiration cytology(FNAC) smear obtained from the right parotid gland revealed scattered epithelial cell clusters or nests in a diffuse inflammatory and necrotic background. Some epithelial cells had squamoid appearance showing variable sized bizarre shaped nuclei. They had abundant of dense eosinophilic keratinized cytoplasm. Occasionally, parakeratotic cells were also present. These cytologic findings with significant atypia and necrotic background made diagnosis as squamous cell carcinoma. But, the resection specimen from this patient showed classic Warthin's tumor in addition to abundant areas of inflammation and squamous metaplasia. Metaplastic or infarcted Warthin's tumor in the salivary gland may be confused with false positive diagnosis of malignancy on FNAC. Therefore, cytopathologist should have adequate awareness of potential of erroneous diagnosis in FNAC of Warthin's tumor.