Parathyroid carcinoma: diagnosis and clinical history.

BACKGROUND: Parathyroid carcinoma is often over-diagnosed based on histologic appearance alone. We limited the definition of the disease to patients with recurrence, metastases, or frank capsular invasion on histologic examination.
METHODS: With these criteria, fourteen cases of parathyroid carcinoma seen at our institution from 1955 to the present were identified.
RESULTS: All patients presented with hypercalcemia, and all deaths were due to hypercalcemia. Two patients have been free of disease after initial operation for 31 and 180 months. Six other patients had a prolonged course with a median survival more than 80 months. Two of these patients have undergone one reexcision each for local recurrence, and four have undergone multiple resections for local recurrence or metastases. These reoperations usually resulted in satisfactory, albeit temporary, control of hypercalcemia. Finally, six patients died of disease after an aggressive course, with a short median survival (47 months). Four of these patients were seen in the 1950s before an aggressive approach to metastatic disease was adopted.
CONCLUSIONS: The types of clinical courses observed in this study may be more reflective of the varied biologic features of parathyroid carcinoma and the approach to recurrence than of the initial operations. For patients with recurrent or distant disease, an operation appears to prolong survival and palliate the symptoms of hypercalcemia.