Parathyroid Carcinoma: An Experience from the Indian Primary Hyperparathyroidism Registry

ObjectiveTo describe the details of widely invasive parathyroid carcinoma (WIPC) patients admitted in the Endocrinology department of our institute during the last 22 years and to compare their clinical, biochemical, and hormonal profile with minimally invasive parathyroid carcinoma (MIPC) and sporadic parathyroid adenoma patients.MethodsThis is a retrospective analysis of data from the Indian primary hyperparathyroidism registry.ResultsOf the 547 primary hyperparathyroidism patients in the registry, 5 (2 men and 3 women) had WIPC (0.9%) and 7 (1 man and 6 women) had MIPC (1.3%), with median ages of 45 (interquartile range, 41-51) years and 47 (interquartile range, 28-48) years, respectively. Among the patients with WIPC, renal manifestations were present in 5 patients, skeletal manifestations in 4 patients, and palpable neck masses in 4 patients. Three patients had distant metastases and 2 had cervical lymph node involvement. All 5 patients had surgical resection of their cancers, with persistent disease in 4 patients, but all patients died within 2 years after surgery. One patient with MIPC had a palpable parathyroid nodule; none had lymph nodal or distant metastases. None of the patients with MIPC died during the median follow-up of 18 (interquartile range, 12-18) months. Patients with WIPC had significantly higher serum calcium level compared with sporadic parathyroid adenoma patients with skeletal and renal manifestations.ConclusionAccurate histopathologic classification of parathyroid carcinoma is important as WIPC is associated with a more aggressive clinical course and a higher risk of mortality than MIPC.