Cytomorphological comparison of ThinPrep and SurePath liquid-based cytology in thyroid fine-needle aspiration.

BACKGROUND: The two widely established systems for liquid-based cytology (LBC), ThinPrep and SurePath, employ different principles. The aim of this study was to compare the cytomorphology of thyroid lesions prepared by the two techniques. METHODS: We retrospectively reviewed 44 thyroid FNA specimens prepared by LBC, including 20 ThinPrep and 22 SurePath. Cytologic diagnoses were made according to the Bethesda system and cytomorphologic parameters were evaluated. RESULTS: Acellular smears were significantly frequent in ThinPrep than SurePath (10% vs. 0%). Both techniques produced a clean background, well cell preservation, and not apparent cell shrinkage. ThinPrep showed significantly lower cellularity than SurePath (25% vs. 4.3%). ThinPrep produced considerable flattening and fragmented clusters, while SurePath contained larger clusters in a three-dimensional configuration. Colloid was significantly reduced in amount and fragmented in ThinPrep, and was easily observed in SurePath. In cases of Hashimoto's thyroiditis, ThinPrep produced much less leukocytes in background than SurePath. Aggregates of fibrin and leukocytes were frequently present in 10/16 cases (62.5%) processed by ThinPrep. Air-dry artifact at periphery of the ring was present in 6/16 cases (37.5%) processed by ThinPrep. The nuclear features of papillary carcinoma were similarly evident in both LBC preparations. CONCLUSION: SurePath seems to be superior to ThinPrep for diagnosing benign entities based on adequate representation of colloid and lymphocytes. The cell quality of both techniques in thyroid FNA was comparable, while each method introduces its own unique cytologic artifacts related to its methodology. We should recognize the cytomorphologic alterations to avoid misinterpretations.

Diagnostic values of SurePath liquid-based cytology versus conventional smear in thyroid aspiration samples: A 13-year experience at a single institution.

BACKGROUND: Fine needle aspiration cytology (FNAC) is the most useful tool in the diagnosis of thyroid nodules. Liquid-based cytology (LBC) is replacing the conventional smear (CS) for evaluation of thyroid FNAC. In our institution, thyroid FNAC preparation was changed from CS to LBC SurePath in July 2016. This study aimed to compare the diagnostic value of SurePath with that of CS in thyroid lesions. METHODS: A total of 35,406 samples of thyroid FNAC (11,438 CS and 23,968 SurePath), collected from January 2010 to December 2022, were included in this study. We also examined the malignant rate using the surgical pathology diagnosis as the gold standard. RESULTS: The distribution of TBSRTC cytological categories was equivalent between CS and SurePath. The rate of nondiagnostic/unsatisfactory category was higher in CS compared to SurePath (43.4% vs. 22.3%; p < .05). After routine use of SurePath, the surgical resection rate was reduced from 12.0% to 8.6% (p < .05) and the malignant rate increased from 32.2% to 41.5% (p < .05). The sensitivities of CS and SurePath were 71.0% and 82.0%, respectively, and the specificities were 99.0% and 97.3%, respectively, whereas the positive predictive values were 97.8% and 96.8%, respectively, and the negative predictive values were 85.0% and 84.6%, respectively. Diagnostic accuracy of CS and SurePath were 88.5% and 89.7% respectively. CONCLUSION: SurePath can increase the sample adequacy, increase the sensitivity and reduce the workload and avoid unnecessary surgeries with similar accuracy to CS.