Acinic Cell Carcinoma of the Parotid Gland. Fine Needle Aspiration Cytology Findings

Acinic cell carcinoma is relatively uncommon salivary gland tumor with low-grade malignancy. The tumor possess characteristic cytological findings, however, differential diagnosis is difficult in certain cases. We present a case of acinic cell carcinoma of parotid gland. The patient is a 74-year-old Japanese female. She had noticed cheek swelling during 10 years. Fine needle aspiration cytology was conducted. The smears contained a hemorrhagic back ground with epithelial component. Sheet and cluster of epithelial components are composed of cells with abundant granular cytoplasm. The nuclei were centrally located. In Giemsa stain, the cells had cytoplasmic small vacuoles. PAS positive small granules were identified. The cytologic features of malignancy were minimal. The tumor is considered as acinic cell carcinoma. There after, the tumor was completely resected. Histologically, the tumor was diagnosed as acinic cell carcinoma with solid and micro-cystic growth pattern.