Ectopic secretion of parathyroid hormone in a neuroendocrine tumor: a case report and review of the literature.

Very few cases have been reported in which the production and secretion of intact PTH by a non-parathyroid tumor has been authenticated. This paper describes the case of a 73 year old white female with a clinical and biochemical profile characteristic of primary hyperparathyroidism. Sestamibi scan and comprehensive neck ultrasono-graphy failed to localize a cervical lesion. Because the clinical manifestations were striking, neck exploration was performed. Dissection of the central compartment identified a lesion. PTH levels dropped to normal within ten minutes after its removal. Intraoperative parathyroid hormone assays facilitated the successful surgical removal of the lesion. Pathological examination yielded a diagnosis of a neuroendocrine tumor. These results document the ectopic production of intact PTH by a neuroendocrine tumor and present a novel neoplastic cause of primary hyperparathyroidism. This is the second report of an ectopic neuroendocrine tumor in the head and neck which secreted intact PTH.