Parathyroid Ectopic Tumors, Mediastinal
Mediastinal/substernal parathyroid adenoma; Mediastinal/substernal parathyroid carcinoma; Mediastinal/substernal parathyroid cyst
Tumors of parathyroid origin that arise within, extend into, or metastasize to involve the mediastinum.
Ten percent of parathyroid adenomas are ectopic. Approximately, half of all ectopic parathyroid adenomas occur in the anterior mediastinum due to embryologic origin from the third and fourth branchial pouches. Mediastinal parathyroid carcinoma is rare.
Mediastinal parathyroid tumors can be seen in any age group. The peak incidence of symptomatic parathyroid adenoma is between 50 and 60 years of age. Parathyroid carcinoma can occur at any age.
Parathyroid adenomas and cysts occur more often in women. Gender distribution is equal in parathyroid carcinoma.
Ectopic parathyroid tumors are more common in the anterior mediastinum; however, posterior mediastinal tumors are well documented.