Parathyroid cancer, a continued diagnostic and therapeutic dilemma: report of four cases and review of the literature.

Parathyroid cancer presents a diagnostic challenge as a rare endocrine malignancy usually not recognized preoperatively and often not conclusively identified intraoperatively. We examined a cluster of parathyroid cancers treated at University of Louisville-affiliated hospitals during a 5-year interval. Clinical and histologic data from patient records at University Surgical Associates, the University of Louisville Hospital, Norton Hospital, and the Louisville Veterans Administration Medical Center in Louisville, KY were retrospectively reviewed.