Clinical analysis of 5 cases complicated with mediastinal ectopic parathyroid gland after surgery for secondary hyperparathyroidism

Objective To investigate the clinical characteristics of mediastinal ectopic parathyroid glands complicated after parathyroidectomy（PTX）in patients with secondary hyperparathyroidism（SHPT）. Methods From August 2016 to November 2024，among 321 patients who underwent PTX due to SHPT in China-Japan Friendship Hospital consecutively，5 patients were found mediastinal ectopic parathyroid gland after the first PTX，accounting for 1.6%.The clinical data characteristics of these 5 patients were analyzed. Results Five patients with ectopic parathyroid in mediastinum were all male，with an age of（44.0±5.9）years，a body mass index（BMI）of（29.6±4.7）kg/m2,and the levels before first surgery included serum parathyroid hormone（PTH）level of（2 753±612.20）pg/mL，blood calcium level of（2.6±0.3）mmol/L，bloodphosphoruslevel of（2.3±0.8）mmol/L，and alkalinephosphataselevel of（467.2±197.0）u/L,while the levels after first surgery included PTH level of（2 599.0±796.7）pg/mL，blood calcium level of （2.3±0.1）mmol/L，blood phosphorus level of（2.0±0.6）mmol/L，and alkaline phosphatase level of（480±202.70）u/L. Ultrasound and CT examination did not indicate mediastinal ectopic parathyroids before the first operation，but radionuclide computed tomography showed the presence of mediastinal ectopic parathyroids after the first surgery. Three of the patients underwent secondary surgery，including open neck surgery and thoracoscopic surgery，respectively，and the PTH levels returned to normal after operation without complications. Two cases did not undergo further surgical treatment and were treated with drugs such as cinacalcet and calcitriol. Conclusion The incidence of ectopic parathyroid glands in the mediastinum after PTX in SHPT patients is approximately 1.6%，with a higher prevalence in males. Patients often meet the criteria for obesity based on their BMI，and there is a significant increase in preoperative PTH levels，along with preoperative serum calcium levels exceeding the normal range. Enhanced CT reading experience helps to improve the diagnosis rate，and radionuclide tomography has a certain diagnostic significance. Spplementary surgery can achieve satisfactory results.