Morphologic predictors of papillary carcinoma on fine-needle aspiration of thyroid with ThinPrep® preparations

Although the cytologic features of papillary carcinoma of the thyroid are well-known, none is entirely specific. We conducted this study to determine the minimal criteria necessary to achieve 100% specificity fbr the diagnosis of papillary carcinoma on fine-needle aspiration (FNA). Forty patients with histologically confirmed papillary carcinoma and 17 patients with other thyroid lesions who underwent preoperative FNA at Beth Israel Deaconess Medical Center during a 4-yr period were included in the study. All cytology slides were prepared with the ThinPrep (R) processing technique. Various architectural and nuclear features were evaluated with a score assigned to each feature, and correlated with the histologic diagnosis of papillary carcinoma. tranuclear inclusions, papillary and/or sheet arrangements, nuclear grooves, powdery chromatin, nuclear molding, high cellularity and small nucleoli were significantly associated with papillary carcinoma (P < 0.05). The requirement of any intranuclear inclusions and many nuclear grooves, or a minimum of sum of scores (of the above eight features) of 10, yields 100% specificity and approximately 70% sensitivity Cases with Server features can be reported as suspicious or indeterminate for papillary carcinoma. A quantitative/probabilistic approach in the reporting of thyroid FNA provides a practical guide for management of patients with thyroid modules. (C) 2001 Wiley-Liss, Inc.