Incidence and prognosis of parathyroid gland carcinoma: A population-based study in The Netherlands estimating the preoperative diagnosis

BACKGROUND: Parathyroid carcinoma is a rare malignancy and generally is diagnosed after surgery for primary hyperparathyroidism. Lack of a preoperative diagnosis and ill-considered surgical planning with its impact on survival are ill-described. METHODS: In a retrospective population-based cohort study the clinical features, treatment, recurrences, and survival of 41 parathyroid cancer patients are reported and compared with characteristics of patients with primary hyperparathyroidism. RESULTS: Patients with parathyroid carcinoma had significantly higher serum parathyroid hormone and calcium levels compared with patients with primary hyperparathyroidism. Nineteen patients (46%) had a palpable neck mass. A parathyroid hormone level more than 3 times the upper normal limits was suspicious and levels more than 10 times carried a positive predictive value of 84% for carcinoma. Ten-year recurrence-free and disease-specific survival rates were 71% and 79%, respectively. CONCLUSIONS: Parathyroid hormone levels of more than 3 times upper normal limits, palpable neck mass, and profound hypercalcemia are suspicious signs of carcinoma necessitating surgical exploration by an experienced surgeon. (C) 2011 Elsevier Inc. All rights reserved.