Endocrine Abstracts

Background: The presence of secondary tumors to the thyroid is well known, although a rare entity (0.5–1.2%). The simultaneous appearance of papillary carcinoma and metastasis from hip osteosarcoma has never been reported.

Case presentation: The patient is a 60 year old female who presented with a suspicious left thyroid nodule and a long history of osteosarcoma. The preoperative FNA of the left thyroid nodule was consistent with papillary malignancy (Bethesda classification VI). In January 2019 she had a total thyroidectomy for a multifocal papillary carcinoma with two positive lymph nodes from a total of three pretracheal (delphian) nodes excised and a 6.2 cm metastatic osteosarcoma of the left thyroid lobe with extensive necrosis and mixed cartilaginous and osteoid production, infiltrating the strap muscles. Postoperatively she was treated with Iodine ablation. Thyroiditis Hashimoto was also present. In January of 2018 she had a tumor excised from the base of her tongue. The histologic examination showed a malignant neoplasm from peripheral nerve sheaths. In July 2017 the FDG PET-CT showed a left upper lung lobe metastatic nodule and a hypodense left thyroid nodule. She had a left upper lobectomy for a metastatic osteosarcoma of 4.3 cm size. Postoperatively she was treated with pazopanib 800 mg/day, (a tyrosine kinase inhibitor also used successfully in treating thyroid carcinoma). In 2012, she was diagnosed with a sacral bone chondroblastic osteosarcoma which was completely excised.

Conclusions: Secondary tumors of the thyroid together with papillary carcinoma may rarely happen and is a diagnostic problem. Its presence often indicates a poor prognosis.