Tumoral Calcinosis is a rare condition that can be mistaken clinically for sarcoma. It is a tumor-like lesion. Tumoral Calcinosis is a common topic that may appear on exams because it looks like a tumor. Tumoral Calcinosis occurs more often in people of African descent as well as females; the condition may be hereditary—the etiology is not fully understood. It is a spontaneous periarticular calcification. It occurs around joints, especially the hip and shoulder joints.
There is another entity called calcinosis of renal failure or uremic tumoral calcinosis. It appears similar to Tumoral Calcinosis and occurs in patients with renal failure or in patients who are on long term dialysis. Patients will typically have hyperphosphatemia and hypercalcemia. There is less involvement of the hip and shoulder than with tumoral calcinosis.
During the physical examination, you will find an enlarged, firm, nontender, fixed, and painless mass. It will limit the movement of the patient and also limit the ambulation. There shouldn’t be a history of trauma.
X-rays will show extra-articular multiloculated mineralized masses around the joints. CT scans and MRIs may show fluid inside the mass. A bone scan will probably show hot spots (dark areas).
Labs will show that calcium levels may be normal in non-renal types. A biopsy of the lesion will show hydroxyapatite calcium deposits with surrounding macrophages (no crystals).
There are multiple differential diagnosis, for example:
Chondrosarcoma
Malignant tumor
Contains malignant cartilage cells
Synovial Chondromatosis
Occurs inside the joint
Contains metablastic calcified cartilage within the synovium
Myositis Ossificans
Occurs from trauma
It shows zoning phenomenon
Like egg shell calcification in which there is a mature bone formation at the periphery
Parosteal Osteosarcoma
Dense bone forming lesion
Appears to be stuck onto the cortex of the bone
Usually located in the back of the knee
If the patient is asymptomatic, observe the lesion. If the patient is symptomatic, and the mass is enlarging, perform a wide excision to prevent local recurrence.
