Endocrine Abstracts

A 60 year old gentleman with a history of renal stones presented 5 years ago with left sided flank pain. A CT of his renal tract showed an unexpected metastatic deposit in the left iliac crest. Cross-sectional whole body imaging, performed to locate the primary, also identified an expansile soft tissue mass in the T8 vertebral body and a predominantly cystic looking left sided thyroid nodule. He proceeded to have an iliac crest biopsy which was consistent with metastatic follicular thyroid cancer. A dedicated thyroid ultrasound scan showed a malignant looking thyroid nodule with no suspicious lymphadenopathy. He was referred for an urgent thyroidectomy. Post-operative histology was reported as widely invasive follicular thyroid cancer with evidence of vascular invasion and tumour necrosis. He was commenced on suppressive doses of Levothyroxine and was referred to our centre for radioiodine. A repeat look at his pre-operative spinal imaging was worrying for impending spinal cord compression from the T8 metastatic deposit. He, therefore, received urgent radiotherapy to this lesion and to the left ilium. After completing the radiotherapy he received radioiodine ablation. Post-ablation I-131 scan showed iodine avidity in the thyroid bed, T8 and the left ilium. Over the next two years he received four therapy doses of radioiodine with good concentration in the metastatic deposits. His stimulated thyroglobulin fell from 6,840 μg/l to 3,544 μg/l. However, in May 2016, four months after his last radioiodine therapy dose, he reported worsening bone pain. His unstimulated thyroglobulin rose to >5,000 μg/l and a repeat MRI scan showed new acetabular deposits and a left pubic ramus pathological fracture necessitating more radiotherapy to this site. A repeat look at his post-therapy scans confirmed these sites as being non-iodine avid. In view of this, a PET scan was arranged to look for other non-iodine avid sites. Unfortunately, this identified multiple spinal and lung metastases. He was given bisphosphonate therapy and his case was brought back to the thyroid multi-disciplinary team meeting where funding for Sorafenib was discussed. However, the patient had done some of his own research and was keen to enrol in a clinical trial that specifically looked at treatment options which may restore iodine avidity to his advancing disease first. Differentiated thyroid cancers are usually responsive to radioiodine therapy. Refractory follicular thyroid cancers are rare and treatment options are limited. This case highlights the role of the multi-disciplinary team in managing these complex patients.