Design/Setting
Case series based on patients with TC treated in University of California—San Francisco hospitals from 1981 to 1992 and the review of the patients described in the English-language literature.

Patients
The study included a total of 17 patients: 10 women and seven men.

Main Outcome Measures
Sex, age, origin, symptoms, localization, treatment, and morbidity.

Results
Seven men and six women, from 32 to 62 years of age, had known disorders of calcium metabolism, and four women, from 37 to 84 years of age, did not. The main causes of the calcium metabolic disorder were secondary hyperparathyroidism in 11 patients (85%) and primary hyperparathyroidism in two patients. In three patients there was a history of trauma at the involved site and in one patient the origin was unknown. Swelling and pain are the most common presenting complaints. Generalized pruritus was observed in 54% of the patients with metabolic disorders (P<.001) but not in patients without metabolic disorders. Among our patients with metabolic disorders, TC occurred most frequently at the shoulder (46%) and elbow (31%). Eleven patients with secondary hyperparathyroidism had received calcium carbonate to bind phosphate, a high level of calcium in the dialysate, and calcitriol (1,25-vitamin D) either orally, intravenously, or both, and three received epoetin alfa (Epogen). Following parathyroidectomy, the patients with hyperparathyroidism improved symptomatically, although calcifications did not change in size. One patient had the calcifications resected and did well, whereas another was treated by subtotal resection and had a recurrence 3 years later. All four of our patients without a metabolic disorder had complete resection of TC with no recurrence.

Conclusion
We believe TC is becoming more common in uremic patients with secondary hyperparathyroidism because of recent changes in the medical treatment of these patients. The increased use of calcium carbonate to bind phosphate as well as calcitriol and calcium to suppress parathyroid function and possibly epoetin alfa are causing more patients to develop TC.

(Arch Surg. 1993;128:737-745)