Comparative Analysis About Clinical Manifestation and Prognostic Factors of Thyroid Follicular and Hurthle Cell Carcinoma

Background and Objectives Follicular thyroid carcinoma (FTC) is the second common thyroid cancer which comprises about 10% of differentiated thyroid carcinoma. Hurthle cell carcinoma (HCC) is a relatively rare disease that has been classified as a subtype of FTC. However, there have been insufficient reports about these two similar thyroid cancers in South Korea due to low incidences. This study aims to present clinical features and evaluate prognostic factors of FTC and HCC.Subjects and Method We reviewed data of 189 FTC and 12 HCC patients who underwent surgery in our center from January 2000 to December 2020. Variables such as clinical characteristics, surgical method, pathologic result, post-operative treatment, survival rate and prognostic factors were included in our study.Results As for age, 67.2% of patients in FTC group and 33.3% of patients in HCC group were older than 55 years-old (p=0.017). The average tumor sizes of FTC and HCC were 2.98 and 3.1 cm, respectively. The 10-year overall survival rates of FTC and HCC were 96.5% and 100%, respectively. The 10-year disease free survival rates of FTC and HCC were 89.1% and 91.7%, respectively. Subclassification (widely invasive: p=0.036) and initial distant metastasis (p<0.001) were significant prognostic factors in FTC.Conclusion This study will be helpful for diagnosis and treatment of FTC and HCC, which are relatively rare.

Anti-PD-1 Immunotherapy Combined With Stereotactic Body Radiation Therapy and GM-CSF as Salvage Therapy in a PD-L1-Positive Patient With Refractory Metastatic Thyroid Hürthle Cell Carcinoma: A Case Report and Literature Review

Thyroid Hürthle cell carcinoma, known as thyroid eosinophilic carcinoma, is a rare pathological type of differentiated thyroid cancer (DTC), representing 3-4% of all thyroid cancers. However, given the high risk of invasion and metastasis, thyroid Hürthle cell carcinoma has a relatively poor prognosis. Traditional treatment methods have limited effects on patients with metastatic thyroid cancers. Developing a valuable therapy for advanced thyroid carcinomas is an unfilled need, and immunotherapy could represent another choice for these tumors. We herein reported the case of a patient with recurrent advanced thyroid Hürthle cell cancer and positive programmed death-ligand 1 (PD-L1) expression, who suffered tumor progression after re-surgery, radiotherapy, and targeted therapy. It is encouraging that PD-1 inhibitors in combination with GM-CSF and stereotactic body irradiation (SBRT) on metastatic disease have a significant anti-tumor effect.

Pituitary metastases of Hürthle cell carcinoma of the thyroid

An 85-year-old man was referred to endocrinology following the discovery of an incidental pituitary mass on cranial imaging which was thought to be a non-functioning adenoma during an admission with headaches, lethargy, confusion and hyponatraemia. He had a history of Hürthle cell carcinoma of the thyroid treated with total thyroidectomy, ablative radioiodine therapy and thyroxine replacement. Subsequently, he developed metastatic spread to the neck, lungs and skeleton. About 9 months later, the patient had deterioration of vision. MRI showed a rapidly expanding pituitary mass with compression of the optic chiasm. Biochemical investigations confirmed hypocortisolism and hypogonadism. The patient underwent trans-sphenoidal resection of the pituitary mass followed by external beam radiotherapy to the pituitary bed. Histopathology confirmed a metastatic deposit of Hürthle cell carcinoma, which is a rare and aggressive variant of follicular thyroid carcinoma.