Papillary cystic pattern of parotid acinic cell carcinoma-a cyotological observation

Background: Acinic cell carcinoma with a papillary cystic pattern (ACC-PCP) is a rare salivary gland tumor whose detailed cytological features have yet to be determined. We discuss cytological features of this rare entity. CaseAn 80-year-old man seen for a parotid swelling was found cytologically in fine-needle aspiration to have papillary cell clusters consisting of oval to columnar epithelial cells indicating slight nuclear atypism and/or pleomorphism. Epithelial cells had vacuolated and granular or clear cytoplasm. A cytoplasmic “droplet” structure was also observed. Histologically, the parenchyma consisted of oval to columnar epithelial cells indicating papillary projection, cystic or glandular arrangement. Similar to cytological features, tumor cells had vacuolated and granular (PAS-positive granules) or clear cytoplasm. Conclusion: Our results suggest that vacuolated or granular cytoplasmic cells had a papillary arrangement. Although a cytoplasmic “droplet ” structure was identified, details remain unclear.