Parathyroid carcinoma: a clinical study of seven cases of functioning and two cases of nonfunctioning parathyroid cancer.

Seven cases of functioning and two cases of nonfunctioning parathyroid carcinoma are presented together with a general discussion of this disease. Functioning parathyroid carcinoma may be associated with prolonged survival. The morbidity and mortality from this disease are generally related to the prolonged hypercalcemia that occurs. The hypercalcemia is best treated with excision of local recurrences; however, this surgery is most often palliative and seldom curative. The best operative results were obtained when the disease could be localized preoperatively. Neck and mediastinal exploration in the absence of physical or radiographic evidence of recurrence failed to affect serum calcium levels. Two patients with nonfunctioning parathyroid cancer did poorly compared with those with functioning parathyroid carcinoma. The few cases reported in the literature are also suggestive of a more aggressive disease. The failure of this tumor to produce parathyroid hormone may allow it to escape clinical attention until it has achieved an advanced state.