pT1a papillary thyroid carcinomas in pediatric patients

Area of Science:

• Pediatric Endocrinology
• Surgical Oncology
• Thyroid Cancer Research

Background:

• Observational studies suggest incidental papillary thyroid cancer (iPTC) and non-incidental PTC (niPTC) are distinct entities in adults.
• This study investigates iPTC in pediatric patients undergoing thyroidectomy for benign conditions.

Purpose of the Study:

• To determine the incidence of iPTC in pediatric patients undergoing thyroidectomy for benign conditions.
• To compare clinical, histopathologic findings, and outcomes of iPTC with niPTC in pediatric patients.
• To assess the indolent nature and risk profile of pediatric iPTC.

Main Methods:

• Retrospective chart review at Children's Hospital of Philadelphia (August 2010 - February 2023).
• Identification of pediatric patients diagnosed with pT1a papillary thyroid cancer (PTC) post-thyroidectomy.
• Comparison of clinical and histopathologic features between iPTC and niPTC cohorts.

Main Results:

• iPTC identified in 5.1% of pediatric thyroidectomies for benign conditions.
• Compared to niPTC, iPTC showed significantly smaller tumor size (3mm vs 7mm), lower lymphatic invasion (0% vs 60.5%), and less AJCC N1 disease (0% vs 55.8%).
• Most iPTC (95.7%) were low-risk (ATA pediatric), while niPTC had higher intermediate/high-risk classification (14.0%). No iPTC patients showed persistent or recurrent disease during follow-up.

Conclusions:

• Incidental papillary thyroid cancer (iPTC) occurs in 5.1% of pediatric thyroidectomies for benign conditions.
• Pediatric iPTC appears indolent, similar to adults, with minimal invasive features and low recurrence risk.
• Non-incidental PTC (niPTC) in pediatric patients exhibits potential for invasive behavior and should be considered a distinct entity.