Metachronous spread of parathyroid carcinoma to a retropharyngeal lymph node.

Abstract

Parathyroid carcinoma is rare and accounts for approximately 1% of patients with hyperparathyroidism. It is a slowly progressive disease with frequent recurrence and high incidence of local metastasis. Because of the rarity of this tumor, little is known about the pattern of lymph node metastasis. A case of retropharyngeal lymph node metastasis found 2 years after initial diagnosis of parathyroid carcinoma is presented and discussed. A 67-year-old man initially was seen with asymptomatic hypercalcemia, and a 1.7-cm mass was removed along with the left hemithyroid. The mass was found to be parathyroid carcinoma. Serum calcium was again elevated 1 year later, and left neck lymph node dissection revealed an upper jugular lymph node containing parathyroid carcinoma. The patient continued to have an elevated serum calcium level, and a retropharyngeal lymph node was found by MRI and removed the following year. The patient is now without evidence of hyperparathyroidism or recurrent disease at 2-year follow-up. Persistent parathyroid carcinoma is often a clinical challenge because of the difficulty in localizing recurrent tumor. Retropharyngeal lymph nodes should be considered as a possible site of metastasis in patients with parathyroid carcinoma.