Tertiary hyperparathyroidism - Histologic patterns of disease and results of parathyroidectomy

Hypothesis: Patients with tertiary hyperparathyroidism (THPT) commonly have parathyroid hyperplasia and should have a bilateral neck exploration with subtotal or total parathyroidectomy with auto transplantation to obtain long-term cure. Design: A retrospective cohort study. Setting: Tertiary referral medical center. Patients: Thirty-four consecutive patients (21 women and 13 men; mean age, 48 years) who underwent neck exploration for THPT. Main Outcome Measures: Sites and histologic pattern of parathyroid disease, and postoperative normalization of serum calcium and parathyroid hormone levels. Results: Twenty-seven patients underwent initial bilateral neck exploration and 7 patients underwent repeat neck exploration for persistent or recurrent THPT. The mean serum total calcium level was 11.2 mg/dL (2.8 mmol/L) (range, 10.3-13.5 mg/dL [2.6-3.4 mmol/L]) and the mean intact parathyroid hormone level was 355 ng/L (range, 95-1236 ng/L). The THPT was due to 4-gland hyperplasia in 33 patients and a single adenoma in only 1 patient. The parathyroid glands were in the normal position in 23 patients and in ectopic locations in 11 patients (8 intrathymic, 1 carotid sheath, 1 tracheoesophageal groove, and 1 intramuscular). Preoperative localizing studies did not identify ectopic or supernumerary glands in any of the patients (ultrasonography, 14 patients; technetium Tc 99m sestamibi, 15; and magnetic resonance imaging, 7). Persistent (n= 5) and recurrent (n= 2) THPT was more common in patients who had an initial 1- or 2-gland excision instead of subtotal or total parathyroidectomy with autotransplantation (P<.001). Four patients had transient hypocalcemia (<8.0 mg/dL [<2.0 mmol/L]), and no other permanent complications or deaths occurred. Biochemical cure was achieved in 94% of patients with a mean follow-up of 4.8 years. Conclusions: Tertiary hyperparathyroidism is usually due to multiple hyperplastic parathyroid glands, and patients who have initial limited parathyroidectomy have a higher risk of persistent or recurrent THPT.