Introduction Rare and poorly understood hereditary metabolic dysfunction of phosphate regulation associated with massive periarticular calcinosis in the extra-capsular soft tissues Epidemiology demographics more common in females and African-Americans onset in childhood or early adolescence location around joints, primarily the hip (trochanteric bursa is most common location) > shoulder Pathophysiology unknown inborn abnormality of phosphorus metabolism Presentation Symptoms mass or swelling typically around joints pain secondary to compression of normal surrounding structures Physical exam inspection palpable mass around joint Imaging Radiographs amorphous, cystic, lobular (circular or oval) well-demarcated calcification in periarticular location direct involvement of the bones or joints is rare CT findings may demonstrate fluid-fluid levels within some of these masses calcium layering ("sedimentation sign") or may have homogenous appearance reduced metabolic activity, lower likelihood of growth MRI findings diffuse, low signal intensity bright, nodular pattern with alternating areas of high signal intensity and signal void may demonstrate fluid-fluid levels (as with CT) Bone scan radionuclide bone scan may reveal intense uptake in the calcific masses Studies Labs normal or slightly elevated renal and parathyroid function normal or slightly elevated serum calcium, phosphorus, uric acid, and alkaline phosphatase Histology lobulated soft tissue masses with well-defined capsules and thick septae masses are filled with calcareous material (calcium phosphate, calcium carbonate and calcium hydroxyapatite) and fluid Differentials Calcinosis of renal failure (secondary tumoral calcinosis) approximately 1% prevalence of periarticular masses may occur independent of concomitant hyperparathyroidism no radiologic/histologic differences with primary tumoral calcinosis diagnosis is based on vitamin D levels, GFR, hyperphosphatemia, and history of chronic renal failure/long term dialysis Calcific tendinitis shoulder > hip > elbow > wrist > knee occurs within tendon no sedimentation of calcium (makes it different from tumoral calcinosis) Synovial osteochondromatosis occurs within joint/tendon sheath "rings and arcs" and intra-articular location (makes it different from tumoral calcinosis) Myositis ossificans and heterotopic ossification not lobular evolves rapidly from faint calcification to organized cartilage and bone in 6 weeks late lesions of HO have well developed cortex and medullary cavity Gout may have hyperuricemia focal erosions of underlying bone Treatment Nonoperative observation indications treatment of choice for non-symptomatic lesions Operative complete surgical excision indications treatment of choice for symptomatic lesions technique complete surgical excision is required to decrease the rate of local recurrence results risk of recurrence if lesion is poorly circumscribed if excision is performed while lesion is actively growing Complications
QUESTIONS 1 of 3 1 2 3 Previous Next (OBQ07.29) A 30-year-old African-American female presents to your clinic with right hip swelling. These symptoms have been present for over 3 years, but this is the first time she is seeking treatment. Figures A-E show radiographs, an MRI, and histology. What is the most likely diagnosis? Review Topic QID: 690 FIGURES: A B C D E 1 Osteochondroma 4% (18/509) 2 Chondrosarcoma 5% (26/509) 3 Dedifferentiated chondrosarcoma 8% (42/509) 4 Tumoral calcinosis 64% (325/509) 5 Bizarre Parosteal Osteochondromatous Proliferation (Nora's disease) 19% (97/509) Select Answer to see Preferred Response PREFERRED RESPONSE 4 (OBQ08.174) A 59-year-old dialysis-dependent diabetic caucasian female complains of palpable bump over her right hip. She denies pain in the hip and has not noticed any other bumps on any of her extremities. On physical exam, the bump is nontender and does not limit range of motion. A radiograph is provided in Figure A. What is the most likely diagnosis? Review Topic QID: 560 FIGURES: A 1 Calcinosis of renal failure 74% (1125/1514) 2 Synovial chondromatosis 7% (99/1514) 3 Synovial sarcoma 1% (13/1514) 4 Parosteal osteosarcoma 6% (94/1514) 5 Myositis ossificans 11% (173/1514) Select Answer to see Preferred Response PREFERRED RESPONSE 1 Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK