Cytomorphologic features of papillary cystadenocarcinoma of the parotid

The fine-needle aspiration cytology findings in four cases of recently classified cystadenocarcinoma of the parotid gland are reported. In three cases a recurrent tumor was aspirated. Smear preparations in all four cases were cellular, with numerous papillary projections, single cells, and sheets of cells in varying proportion in a proteinaceous to mucoid background. The background mucin was in varying proportions. The cells were cuboidal to tall columnar with basal nuclei and mild pleomorphism. The cytoplasm was dense in three cases with variable amounts of mucin. In one case (Case 4) the epithelial cells resembled mucin-secreting goblet cells, while in another case (Case 1) the cytoplasm showed multiple vacuolations. Mitosis was rare. Lymphoid tissue was seen in one case while macrophages and giant cells were seen in two cases. Epidermoid differentiation was absent in all four cases. Pathologic evaluation of the resected tumor confirmed the cytologic diagnosis. Clinical and radiologic evaluation failed to reveal any other potential primary site. Papillary cystadenocarcinomas of the parotid are rare but can be accurately diagnosed on FNAC. However, they need to be differentiated from mucoepidermoid and papillary acinic cell tumors.