Risk of malignancy and diagnostic accuracy of fine-needle aspiration biopsy in thyroid nodules with diameters greater than 4 centimeters

The necessity of fine-needle aspiration biopsy in surgical decision-making for thyroid nodules larger than 3 cm

Ultrasound-guided fine-needle aspiration biopsy (FNAB) is an essential diagnostic tool for detecting malignancy in thyroid nodules. The objective of this study was to evaluate the necessity of FNAB in the treatment decision-making process for thyroid nodules exceeding 3 cm in size. The records of patients who underwent thyroidectomy in our center between 2018 and 2023 were retrospectively reviewed. The study included patients with an index nodule size exceeding 3 cm. Exclusion criteria were missing data, treatment for a different oncological condition, recurrent disease, and purely cystic nodule. Patients were categorized into 2 groups based on the size of the index nodule: Group 1 included nodules measuring between 3 to 4 cm, and Group 2 included nodules 4 cm and larger. Demographic data, FNAB results, and histopathological findings were recorded. The specificity, sensitivity, false negative, and false positive rates of FNAB were calculated. There were 1935 patients who underwent thyroidectomy within the specified date range. In 359 of these patients, the index nodule size was 3 cm or more. There were 188 patients with nodule size between 3 and 4 cm. The mean age was 50.42 ± 13.34 years, and 257 patients were female (F/M ratio = 2.5/1). Fine needle aspiration biopsy was performed on 237 patients, resulting in 65 false negatives. Both the incidence of malignancy and the rate of FNAB false negatives were higher in nodules measuring 4 cm or larger. This study identified a high malignancy rate and a significant rate of false negatives in FNAB of thyroid nodules larger than 3 cm. These findings highlight the importance of carefully considering these factors in the surgical planning of such nodules.

Approach to Thyroid Nodules: Diagnosis and Treatment

Thyroid nodules (TNs) are prevalent and found in up to 50% of individuals. While most TNs are benign, some can be malignant. The evaluation of TNs is crucial to rule out malignancy and identify those requiring surgical intervention. This study aimed to clarify the reported prevalence of TNs, focusing specifically on their various types, assessment and diagnostic processes, current evaluation methods, and evidence-based management. It also provides recommendations for follow-up. TNs are typically found during physical exams or incidentally during imaging procedures. Routine laboratory and clinical evaluations of TNs are common. Ultrasound is the preferred imaging method to determine if a TN needs a biopsy. Fine-needle aspiration (FNA) is crucial in deciding whether surgery or surveillance is necessary. TNs that show suspicious features on the ultrasound may require cytologic analysis to assess the risk of malignancy. The effectiveness of several supplementary molecular tests is still uncertain, although some studies report promising results. The management and treatment approach for TNs primarily depends on the results of FNA cytology and ultrasound characteristics. The optimal treatment strategy for TNs ranges from straightforward follow-ups for low-risk cases to surgical intervention for high-risk patients. Rather than adopting a uniform approach, clinicians should assess each patient on a case-by-case basis using current knowledge and a collaborative, multidisciplinary method.