TPO gene mutations associated with thyroid carcinoma: Case report and literature review

The thyroperoxidase (TPO) genetic variants in thyroid carcinoma is scarcely reported. We report on a pedigree of thyroid papillary carcinoma and hypoechoic thyroid nodules with the TPO gene mutations. The compound heterozygotic mutations of the TPO gene (c.2268-2269 insT and c.2090 G>A) in two patients with congenital goiters hypothyroidism were demonstrated. Fifteen family members of the proband and 105 control individuals were enrolled. The participants underwent clinical examination and molecular screening for TPO mutation. The hypoechoic thyroid nodules underwent fine needle aspiration biopsy. The mutation c.2268-2269 insT was detected in the four family members with normal thyroid hormone levels. The other two members harbored the c.2090 G>A mutation. The heterozygotes had degeneratively hypoechoic thyroid nodules. The control individuals showed no mutation. The maternal grandfather developed a multifocal papillary thyroid carcinoma with lymph gland and nerve invasion in the left lobe of the thyroid gland. The maternal grandfather harbored the TPO c.2268-2269 insT mutation but without BRAFV600E mutation. Malignant cells were not observed in other members by fine needle aspiration biopsy. TPO genetic variants may be associated with thyroid carcinoma and hypoechoic thyroid nodules in a few cases. Long-term follow-up in the pedigree with congenital goiter is reasonable.