An audit of cytopathology in the oral and maxillofacial region: 18-year experience.

OBJECTIVE The aim of this study was to perform an audit of oral and maxillofacial specimens submitted for cytologic diagnosis to verify the importance of this complementary exam. METHODS A retrospective analysis of our institutional cytopathology database was performed over an 18-year period. Clinical information and cytological data were collected. Associations between independent variables and outcomes were assessed using the Pearson chi-square test or Fisher's test, with a 5% significance level. When available, the histologic diagnosis was compared with cytologic diagnosis to identify the percentage of agreement and the specificity, sensitivity and accuracy of cytology in identifying malignant neoplasms. RESULTS A total of 1,082 cases were identified that comprised 65 different cytological diagnoses. Exfoliative cytology (EC) was performed in 312 cases (29.1%) and fine-needle aspiration cytology (FNAC) in 770 cases (70.9%). EC was mainly employed to diagnose oral infectious diseases (P < 0.001) and FNAC to diagnose neoplasms, cystic, reactive and miscellaneous lesions (P < 0.001). Cell block was performed in 555 FNAC cases (51.3%). Panoptic, Papanicolaou and hematoxylin-eosin staining was performed in FNAC and periodic acid-Schiff in EC (P < 0.001). In 211 cases (19.5%), the histologic diagnosis was available and the percentage agreement with the cytologic diagnosis was 41.2%. Sensitivity, specificity, positive predictive value, negative predictive value and accuracy to identify malignant neoplasms were 84.6%, 100%, 100%, 77.8% and 90.0%, respectively. CONCLUSIONS EC was mainly performed for diagnosis of infectious diseases and FNAC for diagnosis of salivary gland tumours, odontogenic lesions, reactive lesions, and cervical metastasis.