Endocrine Abstracts

Introduction

Follicular thyroid carcinoma (FTC) has metastasis in 10-15%; papillary thyroid carcinoma (PTC) rarely metastasizes. Bone metastasis are rare and can cause pain, fractures and spinal cord compression.

Case-1

72 year-old male referred to the hospital with lower back pain. Imaging examination revealed lytic lumbar lesions. Thoracic-abdominal-pelvic-CT showed trachea compression by a multinodular right thyroid lobe. Thyroid-US revealed a 35 mm nodule in that lobe – FNAC: Bethesda IV. Biopsy of one lytic lesion showed thyroid carcinoma metastasis. Total thyroidectomy was performed – histology: PTC. Therapy with ¹³¹I took place; post-treatment ¹³¹I-scintigraphy revealed low back hyperfixation. During follow-up, he maintained signs of bone metastases, confirmed by FDG-PET-CT. Heunderwent radiotherapy and further ¹³¹I treatment. The disease progressed with bone and pulmonar lesions and eventually he lost his mobility. He declined TKI treatment and died 4 years after diagnosis.

Case-2

59-year-old female referred to the hospital, in 2011, with inferior limb pain. Pelvic-CT revealed lesions around the left iliac bone: biopsy revealed FTC metastasis. A thyroid-US showed a 32 mm left lobe nodule – FNAC: Bethesda V. She underwent total thyroidectomy (histology: FTC) and ¹³¹I; post-treatment ¹³¹I-scintigraphy showed hyperfixation of ileum, sacrum and scapula. Before any further treatment, she died with generalized bone metastatic disease.

Case-3

76-year-old female (prior history of right hemithyroidectomy in 2014, for benign nodular goiter) sent to neurosurgery in 2018, with occipital headache. Brain-MRI showed lytic lesions of the occipital bone: biopsy revealed FTC metastasis. Thyroid-US showed 2 nodules on the remaining thyroid (18 mm; 7 mm) – FNAC: Bethesda IV. Totalization of thyroidectomy was performed – histology: NIFTP. She underwent ¹³¹I therapy. Post-treatment ¹³¹I-scintigraphy revealed hyperfixation of the thyroid bed, occipital bone (confirmed by brain-MRI), right ribs and lung. After another ¹³¹I therapy, scintigraphy showed persistent disease. Radiotherapy is on demand.

Case-4

In 2015, a 82 year-old female was admitted to the hospital with thoracic pain. Thoracic-CT showed a 38 mm pulmonary nodule and sternum lytic lesion (histology compatible with FTC metastasis). Thyroid–US revealed a 22 mm left lobe nodule – FNAC: Bethesda VI. Total thyroidectomy took place in 2016 – histology: FTC. ¹³¹I therapy was proposed. Post-treatment ¹³¹I-scintigraphy revealed hyperfixation of the thyroid bed, sternum and lungs, confirmed by thoracic-CT. The patient underwent a second ¹³¹I therapy, but the disease progressed. She refused further treatment and died 1 year later.

Conclusion

These cases show rare presentations of differentiated thyroid carcinoma. We must pay attention to ostearticular complains, especially in the presence of thyroid nodules or previous thyroid surgery.