Endocrine Abstracts

JOINT3600

Introduction: Secondary hyperparathyroidism (SHPT) and coexisting papillary thyroid carcinoma (PTC) have been reported in sporadic cases and studies are scarce. The mechanism linking these two pathologies remains unclear. As a minimally invasive approach to parathyroidectomy has replaced bilateral neck exploration, a thorough preoperative thyroid evaluation is necessary to identify concomitant papillary carcinoma. We aim to report a case associating secondary hyperparathyroidism and thyroid papillary carcinoma.

Case report: This is a case of a 36-year-old woman with chronic renal failure, not on haemodialysis for IgA nephropathy, who was referred for hyperparathyroidism with a parathyroid hormone level of 334 pg/l and a calcemia of 2.08 mmol/l. Neck ultrasound showed a right lobar thyroid nodule of 19*13*10 mm, EUTIRADS 5 grade, with no pathological parathyroid gland. This was supplemented by a parathyroid scintigraphy, which showed no evidence of a pathological parathyroid gland. Fine needle aspiration of the thyroid nodule was inconclusive. The patient underwent a right thyroid lobectomy. Intraoperative frozen section analysis revealedtwo foci of papillary thyroid carcinomameasuring 1.4 cm and 1.7 cm, necessitating completion thyroidectomy and right recurrent mediastinal dissection. A subtotal parathyroidectomywas also performed. The final histopathological examination confirmed the PTC in the right lobe of thyroid, without lymph node involvement and parathyroid hyperplasia. The patient was therefore referred to nuclear medicine department for additional treatment with radioactive iodine.

Discussion/Conclusion: The prevalence of thyroid papillary carcinoma is high in patients with secondary hyperparathyroidism, compared with thyroidpapillary carcinoma in the general population. Most thyroid papillary carcinomas with SHPT are occult thyroid carcinomas and present no significant difference in terms of tumor pathological features and prognostic staging. It is necessary for surgeons to perform more adequate preoperative examination and be more careful during surgery to avoid missing the coexistence of thyroidpapillary carcinoma in patients with secondary hyperparathyroidism. Disclosure of interest: none declared