Low Grade epithelial neoplasm with papillary configuration, favor papillary oncocytic cystadenoma.
Smears show a highly cellular specimen with multiple complex intricately brancying papilary groups with epithelial and connective tissue components. The epithelial cells surrounding the papilla are stratified, monomorphic, bland, without any evidence of nuclear pleomorphism, atypia or mitosis. I favor the possibility of a benign papillary oncocytic cystadenoma, but cannot entirely rule out the possibility of a well differentiated low grade cystadenocarcinoma. Papillary cystadenomas, in the opinion of some authors, represent a Warthin tumor without lymphoid stroma, but many do not support this. Some report that cystadenomas are probalby intraductal papillomas
Differential between cystadenoma and low grade cystadenocarcinoma is sometimes subtle. Distinction requires identification of stromal invasion by cystadenocarcinomas, so complete surgical removal with step pathologic sections are recommended to rule out the possibility of low grade malignancy. The prognosis of cystadenomas and cystadenocarcinomas in parotid is good if complete surgical excision performed.