Despite the clinical utility of fine-needle aspiration for the diagnosis of salivary pathologies, salivary lesions remain one of the most challenging areas in cytopathology. This is partially because there is no consensus on how to report salivary gland cytopathology, which has resulted in inconsistent terminology among institutions and individual cytopathologists and in confusion in communication among cytopathologists and ordering providers.
To summarize our experience with an institutional salivary gland cytopathology reporting system, as an initiative to promote collaborative work toward a consensus on a reporting system.
We developed an empirical 6-tier classification reporting system. Slides of 107 salivary gland fine-needle aspirations with subsequent histology slides were reviewed and reclassified using the 6-tier system. The performance of the cytology reporting system was evaluated with the histology diagnoses serving as the gold standard.
Fine-needle aspiration diagnoses made based on the institutional 6-tier classification system were generally consistent with histology diagnoses for the disease spectrum reported in this study. The sensitivity, specificity, positive predictive value, and negative predictive value for diagnosing malignancies with the system were 86% (12 of 14), 93% (40 of 43), 80% (12 of 15), and 95% (40 of 42), respectively. The risk of malignancy increased from 0% (0 of 13) for negative for neoplasm to 7% (2 of 29) for benign neoplasm, 67% (2 of 3) for suspicious for malignancy, and 83% (10 of 12) for positive for malignancy.
The institutional 6-tier system provides a succinct, risk-of-malignancy-based system to report salivary gland cytology. Our experience with this system helps to pave the way for the adoption of the Milan System for Reporting Salivary Gland Cytopathology.