The use of toluidine blue in locating abnormal parathyroid tissue at operation.

The use of toluidine blue solution infused intraoperatively in order to stain selectively abnormal parathyroid tissue was assessed in nine patients with the clinical diagnosis of hyperparathyroidism. There was one case of hyperplasia, one of carcinoma and seven of solitary adenoma. In all cases abnormal parathyroid tissue could be distinguished from adjacent neck tissue. Staining was of particular benefit in the cases of parathyroid tissue in ectopic sites. Dye infusion was tolerated well and all patients had an uncomplicated postoperative course. No cardiotoxicity was apparent. In five patients who had undergone radioimmunoassay studies of parathyroid hormone the use of toluidine blue was also found to be of assistance.