Low grade papillary adenocarcinoma of minor salivary gland origin - Diagnosis by fine needle aspiration cytology

OBJECTIVE: To describe the diagnostic cytologic features of low grade papillary adenocarcinomas of minor salivary gland origin (LPA) along with its pertinent differential diagnostic entities. STUDY DESIGN: The study was based on a histologically confirmed case of LPA that recurred after multiple excisions. Fine needle aspiration (FNA) was performed during the most recent recurrence. RESULTS: Low-power examination showed geographic sheets and papillary groups of epithelial cells. Individual cells were medium sized, with scant cytoplasm, finely clumped chromatin and occasional prominent nucleoli. Pleomorphism was conspicuously absent. Differential diagnosis included cellular mixed tumor, basal cell adenoma, basal cell adenocarcinoma, low grade mucoepidermoid carcinoma and metastatic papillary carcinoma. CONCLUSION: LPA can be accurately diagnosed by FNA biopsy. However, the cytopathologist must entertain and exclude various differential diagnostic entities.