Cystic parathyroid lesions

Cystic lesions in parathyroid glands are often incidentally discovered, but in general, the cystic component has no clinical significance. This chapter primarily focuses on cystic parathyroid lesions (CPLs) with a predominantly cystic component large enough to be clinically significant. CPLs arise in two different settings: (1) as a true cyst with an epithelial lining, which are usually referred to as nonfunctional parathyroid cysts (NFPCs) and (2) as the cystic degeneration of an adenoma, also referred to as functional parathyroid cysts (FPCs). Whereas the former is usually asymptomatic, the latter is commonly associated with symptoms of hyperparathyroidism.