Endocrine Abstracts

Introduction: Papillary thyroid carcinoma (PTC) is the most common endocrine malignancy. It represents over 80% of all follicular derived well-differentiated thyroid cancers. Despite the fact that the majority of PTCs are well differentiated and have a low rate of local invasion, recurrences, or metastases, there are complex cases which require a multidisciplinary team for a favourable result.

Methods: Clinical examination, blood tests, scintigraphy, CT scan, radioiodine therapy.

Case: We present the case of a 67-year-old woman who underwent a total thyroidectomy in 2019 for multinodular goitre with Graves’ disease, which at the pathological report turned out to be papillary thyroid carcinoma in the right thyroid lobe. She received 1 dose of radioiodine therapy one month after the surgery (100 mCi ¹³¹I) and did a whole-body scintigraphy which revealed iodine fixing areas in the right thyroid lodge, both lungs (pulmonary metastases), right parietal dura mater, left iliac bone and left femur (bone metastases). Four days after the iodine therapy, the patient developed a partial seizure and left hemiparesis and hypoesthesia caused by the brain metastasis. She underwent tumoral resection in the Neurosurgery Department but the neurological deficit and hypoesthesia didn’t improve, while the pathological report concluded the growth was a PTC metastasis. Six months after the thyroidectomy the patient did another dose of radioiodine therapy (135 mCi) with no spontaneous TSH increase after LT4 withdrawal, so she was administered Thyrogen which secured a good uptake of radioiodine in the tumour. She then did a whole-body scintigraphy which revealed a reduction of the primary and secondary lung lesions and stable bone metastases, with no cerebral uptake. Also, the thyroglobulin (TG) decreased every time she did radioiodine therapy. Eighteen months after the thyroidectomy she underwent a third dose of radioactive iodine (100 mCi) which revealed stable lesions. The patient will therefore return for a fourth dose of radioiodine therapy two years after the thyroidectomy.

Discussions: This patient initially presented with a multinodular goitre and Graves’ disease which turned out to be PTC at the pathological report. She has multiple metastases which require a multidisciplinary approach. Also, it is important to note that the TG drops every time she undergoes radioiodine therapy.

Conclusions: PTC is a common endocrine carcinoma which in rare cases can metastasise and severely affect the quality of life of the patients.

Keywords: papillary thyroid carcinoma, metastases, radioiodine therapy.