Clinical Report: Exploring the Uncommon Combination: Thyroid Hemiagenesis with Thyroid Cancer

Overview

This report details two cases of thyroid hemiagenesis (THA) complicated by thyroid cancer (TC), highlighting the rarity of this combination. A review of 32 documented cases over the past 50 years reveals a predominance of papillary thyroid carcinoma among affected individuals.

Background

Thyroid hemiagenesis is a rare congenital condition that can lead to various thyroid pathologies, including cancer. The coexistence of THA and TC is particularly uncommon, making it crucial for healthcare professionals to recognize and understand this association. Accurate diagnosis and management are essential, as surgical intervention remains the primary treatment modality.

Data Highlights

Key Findings

• Thyroid hemiagenesis (THA) is a rare congenital anomaly with a prevalence of 0.02–0.2%.
• The simultaneous occurrence of thyroid carcinoma (TC) in THA patients is exceedingly rare.
• Among 32 documented cases, papillary thyroid carcinoma (PTC) was the most common type, accounting for 81.3% of cases.
• Most patients underwent surgical intervention, with the extent of resection being debated.
• Diagnostic methodologies for THA with TC are similar to those for typical TC.
• There is a lack of comprehensive data on surgical complications and long-term outcomes for patients with THA and TC.

Clinical Implications

Clinicians should be aware of the potential for thyroid cancer in patients with thyroid hemiagenesis, as early diagnosis and appropriate surgical management are critical. Current treatment approaches should align with established guidelines for differentiated thyroid cancer, emphasizing individualized care.

Conclusion

The coexistence of thyroid hemiagenesis and thyroid cancer presents unique challenges in diagnosis and management. Further research is needed to better understand the implications and outcomes of this rare condition.

Related Resources & Content

1. Conexiant, When Thyroid and Parathyroid Collide, 2026 -- https://conexiant.com/pathology/articles/when-thyroid-and-parathyroid-collide/
2. The Pathologist, When Thyroid and Parathyroid Collide, 2026 -- https://www.thepathologist.com/issues/2026/articles/january/when-thyroid-and-parathyroid-collide/
3. The Association of Papillary Thyroid Carcinoma and Hashimoto's Thyroiditis, 2012 -- https://link.springer.com/article/10.1007/s00423-012-1021-x
4. Frontiers in Surgery, Case Report: Cervical approach for dual mediastinal ectopic thyroid, 2026 -- https://www.frontiersin.org/journals/surgery/articles/10.3389/fsurg.2026.1789284/full
5. BMC Endocrine Disorders, Right thyroid hemiagenesis presenting with a contralateral simple diffuse goiter, 2025 -- https://bmcendocrdisord.biomedcentral.com/articles/10.1186/s12902-025-02047-3
6. ATA Guidelines & Statements, 2025 -- https://www.thyroid.org/professionals/ata-professional-guidelines/
7. Thyroidectomy without radioiodine in patients with low-risk thyroid cancer, 2023 -- https://pubmed.ncbi.nlm.nih.gov/?term=39586309
8. conexiant — When Thyroid and Parathyroid Collide
9. the pathologist — When Thyroid and Parathyroid Collide
10. The Association of Papillary Thyroid Carcinoma and Hashimoto's Thyroiditis
11. Frontiers in Surgery — Case Report: Cervical approach for dual mediastinal ectopic thyroid: clinical utility of 3D imaging in surgical planning
12. Right thyroid hemiagenesis presenting with a contralateral simple diffuse goiter: case report | BMC Endocrine Disorders | Springer Nature Link
13. ATA Guidelines & Statements
14. Thyroidectomy without radioiodine in patients with low-risk thyroid cancer: 5 years of follow-up of the prospective randomised ESTIMABL2 trial - PubMed