Water Clear Cell Adenoma of the Parathyroid Gland: A Forgotten Cause of Primary Hyperparathyroidism.

Water clear cell adenoma of the parathyroid gland is a rare neoplasm composed of large clear cells with foamy cytoplasm and mild nuclear pleomorphism, compressing the residual nonneoplastic parathyroid tissue. The differential diagnosis includes a variety of neoplasms with clear cell features. In this article, we provide an overview of the entity with a historical perspective, in order to help pathologists in distinguishing it from other neoplasms in their daily practice.