Uremic tumoral calcinosis in patients on peritoneal dialysis: Clinical, radiologic, and laboratory features

Background: Uremic tumoral calcinosis (UTC) has been analyzed in uremic patients on hemodialysis, but little is known about UTC in peritoneal dialysis (PD). In this study, we aimed to characterize UTC in uremic patients on PD. Methods: We retrospectively reviewed uremic patients on PD who developed UTC over a 9-year period. Clinical, radiologic, and laboratory features; treatments; and outcomes in those patients were assessed. One of the patients (case 7) is described as a case example. Results: The study enrolled 7 patients with a mean age of 41 years. Mean time from PD to UTC was 45.3 months. All patients were anuric but adequately dialyzed. Cardinal symptoms were local tenderness and limited range of joint motion. Lesions were mostly multifocal (n = 6) and predominantly involved shoulders, hands, feet, hips, and wrists. Metatarsophalangeal joint UTC was misdiagnosed as tophaceous gout in 2 patients. Main laboratory findings were hyperphosphatemia (7.9 ± 0.8 mg ²/dL ²), high Ca×P product [>65 mg ²/dL ² (range: 81.1 ± 11.5 mg2/dL2)], secondary hyperparathyroidism (SHPT) with various levels of intact parathyroid hormone (iPTH: 592.2 ± 315.2 pg/mL;