Parathyroid carcinoma in familial hyperparathyroidism

We present the first reported occurrence of parathyroid carcinoma in familial parathyroid hyperplasia or multiple endocrine adenomatosis, type I. The patient's hypercalcemia persisted through 8 years even though abnormal parathyroid tissue was removed from three separate sites in the neck. The original clinical presentation and review of tissue removed initially from the left thyroid lobe suggested the possibility of parathyroid carcinoma; tissue from the second and third operations (on the right) was histologically benign, showing chief cell hyperplasia. A fourth operation then revealed implants of parathyroid carcinoma unilaterally in the left side of the neck. The patient's brother and sister also had parathyroid hyperplasia, and his mother died of a pancreatic tumor of undocumented cell type. The patient himself had no evidence of pancreatic or pituitary tumor.