Unusual manifestation of parathyroid carcinoma in the setting of papillary thyroid cancer.

OBJECTIVE

To describe a rare manifestation of parathyroid carcinoma in association with papillary thyroid carcinoma.

METHODS

We describe the clinical history, findings on physical examination, results of laboratory studies, imaging findings, and histopathologic features of a woman with 2 previously palpable thyroid nodules and mild hypercalcemia.

RESULTS

A 79-year-old woman presented to our endocrinology clinic for reevaluation of 2 thyroid nodules and long-standing hyperparathyroidism. She initially had undergone assessment 6 years previously, at which time an intact parathyroid hormone level was 89 pg/mL (reference range, 10 to 69) and the serum calcium concentration was 10.4 mg/dL (reference range, 8.2 to 10.2) in conjunction with normal alkaline phosphatase, creatinine, and 25-hydroxyvitamin D levels. Subsequently, she was found to have multifocal papillary thyroid cancer in the right thyroid lobe and a 5-cm parathyroid carcinoma in the left side.

CONCLUSION

Synchronous parathyroid and thyroid carcinomas are extremely rare. To our knowledge, our current case is the first documented patient with parathyroid carcinoma who had a clinical presentation consistent with longstanding mild adenoma in addition to synchronous papillary thyroid carcinoma.