Exploration of Treatment Strategies for Nodular Goiter Complicated with Parathyroid Carcinoma: Experience Summary Based on a Single Case

Purpose Parathyroid carcinoma (PC) is an exceedingly rare malignancy that poses significant diagnostic challenges. This case report delineates the clinical presentation, diagnostic evaluation, and multidisciplinary management of PC, highlighting the pivotal role of complete surgical excision and the diagnostic difficulties arising from its overlapping features with benign thyroid and parathyroid conditions. Methods We report the case of a 58-year-old male with a five-year history of a thyroid mass and progressive bilateral lower limb pain. Diagnostic investigations encompassed comprehensive biochemical analysis, thyroid and parathyroid ultrasonography, contrast-enhanced computed tomography (CT), and parathyroid scintigraphy. The patient had bilateral thyroid masses resected, and postoperative pathology showed right parathyroid carcinoma and left nodular goiter. Therefore, the patient underwent further surgery, including resection of the right thyroid lobe and isthmus, as well as central lymph node dissection. Results Preoperative assessment revealed severe hypercalcemia (4.58 mmol/L) and a markedly elevated parathyroid hormone level (3224 ng/L). Imaging examination revealed nodules in both lobes of the thyroid gland. Histopathological examination of the initial specimen confirmed PC, with positive immunostaining for PTH and a high Ki-67 index (25%). The secondary resection demonstrated PC infiltration into the right thyroid parenchyma; no lymph node metastasis was detected (0/2). Postoperative calcium and PTH levels returned to normal, and no recurrence was observed during the two-year follow-up. Conclusion This case emphasizes that PC should be considered in patients presenting with severe hypercalcemia and a cervical mass. Accurate diagnosis requires integration of biochemical, imaging, and histopathological findings. En bloc surgical resection with clear margins constitutes the cornerstone of curative management and can yield favorable long-term outcomes.