Cytologic Comparison Between Growing and Non-growing Benign Thyroid Nodules Evaluated Using Two Different Growth Criteria

ABSTRACT

Objective: Thyroid nodules are frequent in the adult population. Thyroid fine-needle aspiration biopsy is performed for diagnosing cancerous nodules. It is suggested that biopsy-proven benign thyroid nodules should be followed up clinically, and if they grow, rebiopsy should be performed. However, certain growth criteria have not yet been defined.

Material and Methods: We retrospectively reviewed thyroid fine-needle aspiration records of all patients at Dokuz Eylül University Hospital between January 2006 and June 2009. The nodules that underwent second biopsies were evaluated using two different growth criteria: at least 50% increase in the nodule maximal diameter and 20% increase in at least two nodule dimensions with a minimal increase of 2 mm.

Results: From a total of 4217 thyroid nodules, we evaluated the cytological results of 117 benign thyroid nodules, which underwent follow-up biopsies. No significant difference was observed in the cytological results of the growing group (n:21), which had at least 50% increase in the maximal nodule diameter, and the non-growing group (n:96) (p=0.999). In addition, using the growth criteria of 20% increase in at least two nodule dimensions with a minimal increase of 2 mm, no significant difference was observed in the cytological results of the growing (n:47) and non-growing (n:70) benign thyroid nodules (p=0.700).

Conclusion: According to two different growth criteria, the growth of a benign nodule is not an additional risk factor for cancer.