OBJECTIVE: To assess the value of fine needle aspiration cytology (FNAC) in the diagnosis of pleomorphic adenoma and to determine the cytologic variations responsible for diagnostic errors. STUDY DESIGN: We retrospectively studied 212 cases cytologically diagnosed as pleomorphic adenoma. In 184 a histologic diagnosis was available. Fourteen cases of histologically proven pleomorphic adenomas with a previously erroneous cytologic diagnosis were also reviewed. This study was based on those cases with a histologic diagnosis. RESULTS: The sensitivity and specificity of the cytologic diagnosis of pleomorphic adenoma in our series were 92.6% and 98.4%, respectively. In relation to malignancy, the series showed six false negative and three false positive diagnoses. In those cases correctly diagnosed on aspiration (175), a typical cytologic appearance, with no diagnostic difficulties, was observed in 118 cases (67.4%); the remainder showed cytologic variations. Cellular atypia (20.6%), cystic transformation (7%) and the presence of a cylindromatous pattern (5%) resembling adenoid cystic carcinoma were the most common cytologic variations observed and responsible for the majority of the errors. CONCLUSION: The cytologic variations in FNAC of pleomorphic adenoma must be considered in order to avoid important errors in the preoperative management of and surgical approach to salivary gland lesions.
OBJECTIVE: To assess the value of fine needle aspiration cytology (FNAC) in the diagnosis of pleomorphic adenoma and to determine the cytologic variations responsible for diagnostic errors. STUDY DESIGN: We retrospectively studied 212 cases cytologically diagnosed as pleomorphic adenoma. In 184 a histologic diagnosis was available. Fourteen cases of histologically proven pleomorphic adenomas with a previously erroneous cytologic diagnosis were also reviewed. This study was based on those cases with a histologic diagnosis. RESULTS: The sensitivity and specificity of the cytologic diagnosis of pleomorphic adenoma in our series were 92.6% and 98.4%, respectively. In relation to malignancy, the series showed six false negative and three false positive diagnoses. In those cases correctly diagnosed on aspiration (175), a typical cytologic appearance, with no diagnostic difficulties, was observed in 118 cases (67.4%); the remainder showed cytologic variations. Cellular atypia (20.6%), cystic transformation (7%) and the presence of a cylindromatous pattern (5%) resembling adenoid cystic carcinoma were the most common cytologic variations observed and responsible for the majority of the errors. CONCLUSION: The cytologic variations in FNAC of pleomorphic adenoma must be considered in order to avoid important errors in the preoperative management of and surgical approach to salivary gland lesions.