Calcified debris is admixed with soft tissue and inflammatory cells.
Typically, amorphous calcified deposits are surrounded by a proliferation of chronic inflammatory cells. Although not demonstrated here, macrophages and multinucleated giant cells can frequently be seen.
Tumoral calcinosis is an uncommon lesion composed of ectopic periarticular deposits of calcium hydroxyapatite. These tumor-like calcified masses are most commonly located around the large joints such as the hips, shoulders and elbows. Less commonly, the spine, hand, wrist and feet are affected. These lesions are attached to the soft tissues (muscle, tendon and bone) around the joints, but the bone itself is not affected.
The term tumoral calcinosis most accurately describes the familial condition, seen in young healthy individuals who have inherited an inborn error in metabolism of calcium. It appears that the condition is inherited in an autosomal recessive manner and associated with mutations in the GALNT3 gene or FGF23 gene.1 , leading to decreased renal excretion of phosphorus. Kindreds of similarly affected siblings are common.
On the other hand, the term tumoral calcinosis is routinely used by clinicans and pathologists to describe a morphologically identical lesion that result from secondary conditions such as chronic renal disease, hyperparathyroidism and sarcoidosis. Tumoral calcinosis in these circumstances occur in older patients with co-morbidities.
Tumoral calcinosis typically occurs in young patients (1st and 2nd decades). Approximately two-thirds are black, and there is a strong familial component. The lesion is generally asymptomatic, although depending on the location, compressive symptoms may occur and ulceration of overlying skin can lead of infection. Serum calcium is not elevated, however, there is moderate elevation of serum phosphate (hyperphosphatemia).
In contrast, patients with tumoral calcinosis as a result of renal failure or hyperparathyroidism have elevated calcium levels.
Surgical removal of lesion before the mass becomes too large is recommended. Phosphate binders have not proven to be effective.
1 Weiss SW, Goldblum JR. Enzinger. Enzinger and Weiss' Soft Tissue Tumors. 5th Ed. Philadelphia, PA: Elsevier; 2008: 1063-1067.
2 Vigorita VJ. Orthopaedic Pathology. Philadelphia, PA: Lippoincott Williams and Wilkins; 1999: 55-6.