A case report

Rationale: A hormone-active metastatic Hürthle cell thyroid carcinoma (HCTC) and Graves disease (GD) present a therapeutic challenge and is rarely reported. Patient concerns:We present a 64-year-old male patient, who had dyspnea and left hip pain lasting 4 months. He had clinical signs of hyperthyroidism and a tumor measuring 9cm in diameter of the left thyroid lobe, metastatic neck lymph node and metastases in the lungs, mediastinum, and bones. Diagnosis: Laboratory findings confirmed hyperthyroidism and GD. Fine-needle aspiration biopsy and cytological investigation revealed metastases of HCTC in the skull and in the 8th right rib. A CT examination showed a thyroid tumor, metastatic neck lymph node, metastases in the lungs, mediastinum and in the 8th right rib measuring 20 5.6 4.5cm, in the left acetabulum measuring 9 9 3cm and parietooccipitally in the skull measuring 5 4 2cm. Histology after total thyroidectomy and resection of the 8th right rib confirmed metastatic HCTC. Interventions: The region of the left hip had been irradiated with concomitant doxorubicin 20mg once weekly. When hyperthyroidism was controlled with thiamazole, a total thyroidectomy was performed. Persistent T3 hyperthyroidism, most likely caused by TSH-R-stimulated T3 production in large metastasis in the 8th right rib, was eliminated by rib resection. Thereafter, the patient was treated with 3 radioactive iodine-131 (RAI) therapies (cumulative dose of 515 mCi). Unfortunately, the tumor rapidly progressed after treatment with RAI and progressed 10months after therapy with sorafenib. Outcomes: Despite treatment, the disease rapidly progressed and patient died due to distant metastases. He survived for 28 months from diagnosis. Lessons: Simultaneous hormone-active HCTC and GD is extremely rare and prognosis is dismal. Concomitant external beam radiotherapy and doxorubicin chemotherapy, followed by RAI therapy, prevented the growth of a large metastasis in the left hip in our patient. However, a large metastasis in the 8th right rib presented an unresolved problem. Treatment with rib resection and RAI did not prevent tumor recurrence. External beam radiotherapy and sorafenib treatment failed to prevent tumor growth. Abbreviations: 18FDG-PET/CT= positron emission tomography with 2-deoxy-2-fluorine-18-D-glucose /computer tomography, anti-TSH-R= antibodies against TSH-R, CT= computer tomography, EBRT= external-beam irradiation, FT3= free triiodothyronine, FT4 = free thyroxine, GD = Graves disease, Gy = Gray, HCTC = Hürthle cell thyroid carcinoma, mCi =millicurie, mL =milliliter, R1= Editor: Maya Saranathan. Ethical Approval and Consent to Participate: Our publication is performed in accordance with the Declaration of Helsinki and approved by an appropriate ethics committee. The study was reviewed and approved by the Protocol Review Board (ERIDNPVO-0040/2020) and Ethics Committee (ERIDEK-0083/2020) of the Institute of Oncology Ljubljana, and was conducted in accordance with the Declaration of Helsinki. Written consent of the relatives of the deceased patient was obtained for the