Clinical Scorecard: Somatic Mutations in DICER1 Found in Benign Thyroid Nodules of Adults: Characteristics of a Persistent Follicular Nodular Condition

At a Glance

Key Highlights

• Among 931 adult-onset thyroid nodules, 13 benign nodules harbored somatic DICER1 hotspot mutations combined with truncating variants.
• DICER1-mutant nodules showed continuous growth, with 38.5% exhibiting substantial enlargement over time.
• Pathologically, all DICER1-mutant nodules were classified as thyroid follicular nodular disease (TFND) and demonstrated increased follicular formation in organoid culture.

Guideline-Based Recommendations

Diagnosis

• Pathological evaluation of thyroid nodules according to WHO 2022 classification.
• Genotyping of thyroid nodules via targeted sequencing for DICER1 hotspot and truncating mutations.

Management

• Monitor nodule growth with serial ultrasound; significant growth defined as ≥2 mm increase in two diameters and ≥20% increase in baseline diameter.
• Consider surgical intervention for nodules exhibiting substantial growth or suspicious features.

Monitoring & Follow-up

• Regular ultrasound surveillance to assess nodule size and growth dynamics.
• Clinical follow-up for at least 2 years, as nodules with longer duration showed more substantial enlargement.

Risks

• DICER1-mutant benign nodules have continuous growth potential but are associated with low malignant risk.
• DICER1 mutations are generally mutually exclusive with other thyroid cancer drivers, indicating distinct molecular behavior.

Patient & Prescribing Data

Adults with benign thyroid follicular nodular disease harboring somatic DICER1 mutations

No specific pharmacologic treatments indicated; management focuses on monitoring growth and surgical decisions based on clinical progression.

Clinical Best Practices

• Incorporate molecular testing for DICER1 mutations in adult benign thyroid nodules to identify persistent follicular nodular conditions.
• Use ultrasound criteria to define significant nodule growth and guide clinical management.
• Establish multidisciplinary evaluation including endocrinology, pathology, and surgery for nodules with DICER1 mutations.

References

• WHO Classification of Thyroid Neoplasms 2022
• Foulkes WD et al., 2011, Link between DICER1 mutations and familial multinodular goiter
• Thyroid nodule growth criteria by ultrasound