Preoperative imaging diagnosis for persistent renal hyperparathyroidism

Preoperative localization of remaining parathyroid glands that are responsible for persistent renal hyperparathyroidism (HPT) is essential for re-operation. Of 872 patients who underwent total parathyroidectomy with autotransplantation (PTx) in our department, persistent 2HPT occurred in 35 (4.0%). In 21 of these cases, scintigraphy (²⁰¹TICI or ^99mTc-sestamibi) was performed. If the examination showed an abnormal uptake area, computed tomography (CT), ultrasonography (US) and magnetic resonance imaging (MRI) were performed with a focus on the lesion. Scintigraphy scanning revealed an abnormal uptake area in 17 of the 21 cases. The intact PTH levels in these cases were 250-1300 pg/ml. In 13 of these cases, re-operation was performed. CT revealed a positive result in 12 of the 13 cases with re-operation, and US a positive result in 3. MRI detected a mass lesion in 6 of 9 cases. Residual parathyroid glands were removed from the mediastinum in 9 cases (78.6%) and from the neck in 4 (21.4%). The weight of the removed parathyroid gland ranged from 300 to 8165 mg. It may be possible to detect remaining parathyroid glands if the intact PTH level is more than 250 pg/ml or the glandular weight is more than 300 mg.