Abstract:

Follicular variant of papillary thyroid carcinoma （FVPTC） is commonly found in young and middle-aged women， and cases in children and adolescents are relatively rare. The main driving genes of FVPTC are the RAS oncogene family or B-Raf proto-oncogene serine/threonine protein kinase （BRAF）， and DICER1 gene mutation is rarely reported in this subtype. This article reports a case of recurrent FVPTC with positive DICER1 mutation in an adolescent， aiming to provide reference for the clinical diagnosis and treatment of FVPTC. The patient， a 19-year-old female， underwent total thyroidectomy and central lymph node dissection due to thyroid nodules 5 years ago， and was pathologically diagnosed with follicular tumor of uncertain malignant potential （FT-UMP）； after surgery， the patients did not regularly undergo thyroid-stimulating hormone （TSH） suppression therapy and follow-up as instructed. Two months ago， the patient visited the hospital due to enlarged cervical lymph nodes， imaging suggested tumor recurrence with metastases to both lungs and vertebrae， and multigene testing indicated a DICER1 gene mutation. After comprehensive multidisciplinary consultation， bilateral cervical lymph node dissection was performed， and postoperative pathology confirmed the diagnosis of metastatic FVPTC. Te clinicans should focus on rare gene mutations such as DICER1 in the FVPTC patients， and for adolescent patients， follow-up and formulation of individualized treatment plans should be emphasized to achieve early tumor identification and precise intervention， and improve the long-term prognosis of patients.

Key words: Follicular variant of papillary thyroid carcinoma, DICER1 gene, Multidisciplinary consultation, Adolescent, Case report