Endocrine Abstracts

Introduction: Multiple Endocrine Neoplasia Type 1 (MEN1) represents a rare genetic disorder characterized by a predisposition to various endocrine neoplasms, primarily affecting the parathyroid, endocrine pancreas, and pituitary gland. So far, Papillary Thyroid Carcinoma (PTC) has been detected in more than 25% of individuals bearing the MEN mutation, even though this particular cancer type does not usually belong to the clinical spectrum associated with this condition.

Case report: We report the case of a 48-year-old woman who presented with hypercalcemia (3.17 mmol/l), hypophosphoremia (0.7 mmol/l), and elevated PTH (400 ng/ml). These biological findings were consistent with the diagnosis of Primary Hyperparathyroidism. A familial MEN1 history was confirmed through genetic testing in siblings with a missense mutation in MEN1 gene exon 4. Neck ultrasound was performed, uncovering a suspected malignant left-sided thyroid nodule (EUTIRADS 4) measuring 17 mm in diameter, with an ectopic parathyroid mass situated at the cervicothoracic junction with a diameter of 26 mm. MIBI scintigraphy featured a characteristic uptake in the ectopic parathyroid mass. Considering the presence of severe osteoporosis (T-score in the radius side < -5.9 SD), persistent hypercalcemia, and the young age of the patient, surgical treatment was decided. The patient underwent left hemithyroidectomy, left upper and lower parathyroidectomy. Intraoperative pathology examination revealed incidental PTC. A completion thyroidectomy and lymph node dissection were subsequently performed. The definitive pathological examination revealed adenomas in two parathyroid glands (ectopic and eutopic) and bifocal PTC (15 mm in the left lobe, 10 mm in the right), with lymph node metastasis. Whole-body scan showed iodine uptake in the thyroid bed with no distant metastases. This PTC was staged pT1b(m)N1a M0 with intermediate ATA risk. The patient received 100 mCi radioactive iodine therapy for isotopic ablation with favorable outcomes.

Discussion: Our case underscores a rare occurrence of the association between PTC and MEN1. While PTC is often linked to BRAF V600E mutation other pro-oncogenic mutations, including MEN1 mutation, are also possible. However, this association is not well established. Further cases are required to validate this potential correlation.

Reference: 1. Xu, J. L., Dong, S., Sun, L. L., Zhu, J. X., & Liu, J. (2022). Multiple endocrine neoplasia type 1 combined with thyroid neoplasm: A case report and review of literatures. World Journal of Clinical Cases