The diagnostic value of add-on thyroid cell block in the evaluation of thyroid lesions

OBJECTIVES: Fine-needle aspiration (FNA) cytology plays a pivotal role in diagnosing thyroid nodules. Imaging assessment, followed by thyroid lesion sampling, is a widely applied clinical practice. Tissue fragments remnants are retrieved in cell-block providing an adjunct diagnostic tool for histopathology visualization and use of ancillary testing. This study aimed to evaluate whether the auxiliary application of cell-block adds to the diagnostic accuracy of the thyroid FNA. MATERIAL AND METHODS: A total of 252 thyroid FNA cases between (2020 and 2021) were reviewed from patients aged 18–76. Of those, 150 cell-blocks were recovered and examined to assess their utility. Following categories were plotted during cell-blocks revision: (A) Inadequate material retrieved; (B) cell-block shows similar features along with their accompanying smears; and (C) value added to cytology diagnosis when using cell-block. RESULTS: The distribution of cell-blocks according to the aforementioned classification are as follows: A — non-diagnostic 63%, B — similar observation seen in both preparations 35%, and C — value added to the rendered diagnosis 2%. Hence, the use of cell-block improved cytology diagnosis in only 2% of total cases. Mostly were of immunostains application for diagnosis confirmation. CONCLUSION: The non-diagnostic and atypical cytology cases have not been upgraded to a more meaningful category by the incorporation of cell-block performed with the routine non-enhancement random method. On the other hand, cell-blocks contributed generously toward immunostaining application in malignant scenarios.