summary Tumoral Calcinosis is a rare, hereditary metabolic dysfunction of phosphate regulation associated with development of massive periarticular calcinosis in the extra-capsular soft tissues. Patients most commonly present with palpable lesions around the hip and shoulder. Diagnosis is made radiographically with amorphous, cystic, circular, well-demarcated calcification in a periarticular location. Treatment is observation for asymptomatic lesions. Surgical excision is indicated for symptomatic lesions associated with decreased function. Epidemiology Demographics more common in females and African-Americans onset in childhood or early adolescence Anatomic location around joints, primarily the hip (trochanteric bursa is most common location) > shoulder Etiology Pathophysiology unknown inborn abnormality of phosphorus metabolism FGF-23 defect leading to familial hyperphosphatemic tumoral calcinosis 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