Concurrent Hashimoto Thyroiditis, Graves' Disease, and Papillary Thyroid Carcinoma: A Case Report.

Background and Clinical Significance: The co-occurrence of Hashimoto thyroiditis (HT), Graves' disease (GD), and papillary thyroid carcinoma (PTC) is an extremely rare event and offers a unique opportunity to examine how chronic autoimmune thyroid disease may interact with the process of thyroid cancer development. Case Presentation: We present the case of a 42-year-old female with long-standing autoimmune thyroid disorders who developed progressive Graves'-related orbitopathy that did not improve with corticosteroid therapy. Owing to persistent hyperthyroidism and worsening orbital symptoms, she underwent total thyroidectomy. A histopathological examination of the removed thyroid gland surprisingly found PTC developing within a background of chronic autoimmune inflammation. The patient's postoperative course included stable thyroid hormone replacement, a significant decrease in serum levels of thyroid autoantibodies, and clinical improvement in her orbital symptoms following decompressive surgery, although partial visual impairment persisted.

Conclusions

This case highlights how chronic thyroid autoimmunity may create a carcinogenic environment and emphasizes the importance of comprehensive histopathological assessment and multidisciplinary care for patients with complex autoimmune thyroid disease.