Table 2. Criteria for adequacy and unsatisfactory in the Japanese reporting system for thyroid aspiration cytology 2019.

Adequacy
(I) A minimum of six groups of well-visualized follicular cells, with at least ten cells per group
(II) Abundant colloid
(III) Cells with significant cytological atypia
(IV) Inflammatory cells, such as lymphocytes, plasma cells, or histiocytes
Unsatisfactory
(I) Poor cell preservation (drying degeneration, poor fixation, obscuring blood, clotting artifact, smearing failure, etc.)
(II) None of the above four scenarios listed under adequacy