Papillary cystic type of acinic cell carcinoma of parotid: fine needle aspiration cytological features of a high grade variant with oncocytic metaplasia

A 60-year-old female developed a right parotid swelling six months after surgery for intra-oral squamous cell carcinoma. Fine needle aspiration (FNA) cytological smears showed dissociated large and small pleomorphic tumour cells with abundant mitoses and oncocytic features. A cytological diagnosis of parotid acinic cell carcinoma (ACC) was made. Histological study of the subtotal parotidectomy specimen showed a papillary cystic variety of acinic cell carcinoma (ACC-PCV). FNA cytological features in this case of ACC-PCV differs from the two previously reported cases in that it showed prominent oncocytic and high grade features and absence of papillary pattern in the cytological smears. ACC-PCV is an uncommon tumour and knowledge of its varied FNA cytological features is important for the diagnosis of this neoplasm.