Beyond Malignancy Risk Stratification: FNAC Report Anticipates Thyroid Cancer Staging. Insights From Recent Studies.

Area of Science:

• Endocrinology
• Cytopathology
• Oncology

Background:

• Fine-needle-aspiration-cytology (FNAC) is a standard diagnostic tool for thyroid nodules.
• A significant proportion of FNAC results are indeterminate (ITN), often requiring surgery.
• Previous studies suggested variations in thyroid cancer (TC) behavior based on FNAC findings.

Purpose of the Study:

• To discuss and provide perspective on recent findings regarding the clinical behavior of thyroid cancer with indeterminate FNAC results.
• To compare the clinical presentation of thyroid cancer initially diagnosed as ITN versus those diagnosed as suspicious or malignant.
• To explore the implications of these findings for patient management and treatment strategies.

Main Methods:

• A commentary involving experts and cytologists not part of the original studies.
• Review and synthesis of data from two independent studies (Europe and US) on thyroid cancer clinical behavior.
• Comparison of outcomes based on different cytology classification systems (Italian and Bethesda).

Main Results:

• Thyroid cancer (TC) with an initial indeterminate thyroid nodule (ITN) diagnosis exhibits a less aggressive clinical phenotype.
• Lower rates of lymph node metastasis, aggressive variants, and BRAFV600E mutations were observed in ITN-diagnosed TC.
• These findings were consistent across both European and US studies, regardless of classification system.

Conclusions:

• Preoperative diagnosis of ITN in thyroid cancer is associated with a more indolent clinical course compared to suspicious or malignant diagnoses.
• These results have significant clinical relevance for endocrinologists and cytologists.
• The findings support exploring less aggressive therapeutic approaches for thyroid cancer initially classified as ITN.