Incidentally vs non-incidentally diagnosed papillary thyroid carcinoma: are there differences?

Area of Science:

• Endocrinology
• Oncology
• Pathology

Background:

• Thyroid carcinoma (TC) incidence has risen over 50 years, with unclear causes.
• Distinguishing between incidental and non-incidental TC is crucial for understanding incidence trends.

Purpose of the Study:

• To compare incidental (ITC) versus non-incidental thyroid carcinoma (NITC) based on demographics, clinical presentation, histology, and 5-year outcomes.
• To investigate factors contributing to the increasing incidence of thyroid cancer.

Main Methods:

• Retrospective analysis of 225 papillary TC (PTC) cases with 5-year follow-up.
• Classified cases into ITC (incidentalomas) and NITC (palpable/visible nodules or compressive symptoms).

Main Results:

• ITC patients were older (53.3 vs 47.2 years) with smaller mean tumor size (19.1 vs 28.6 mm).
• No significant differences were observed in histological features, aggressive subtypes, or 5-year clinical outcomes between ITC and NITC.
• NITC cases showed a higher prevalence of advanced pTMN staging (T3a/T4, M1).

Conclusions:

• Older age and smaller tumor size characterize ITC, but histological and 5-year outcome differences with NITC were absent.
• Approximately one-third of ITC cases had tumors >20mm, indicating potential for significant incidental findings.
• Overdiagnosis is the most probable driver of increased TC incidence, as large tumors can be incidentally detected.