Soft Tissue Calcifications

The differential diagnosis for soft tissue calcifications include:

• Heterotopic ossification: Lamellar bone forming in soft tissues (skin, subcutaneous tissues, skeletal muscle, ligaments, and tendons). Three types:
  • Myositis ossificans progressiva: Rare pediatric metabolic disease characterized by ossification of the skeletal muscle.
  • Neurogenic heterotopic ossification: Follows burns or neurologic injury.
  • Traumatic heterotopic ossification: Follows injury to tissue surrounding bones and joints.
• Ectopic calcification: Mineral deposition (not bone formation, as seen in heterotopic ossification) in soft tissues due to trauma.
• Metastatic calcification:
  • Secondary hyperparathyroidism: Calcinosis of chronic renal failure. Soft tissue calcifications usually involve the extremities. Look for other skeletal findings of secondary hyperparathyroidism: Osteopenia, cortical thinning, subperiosteal bone resorption, resorption of secondary trabeculae and accentuation of primary trabeculae.
  • Hypervitaminosis D: Large, calcified, periarticular masses with associated ligamentous & intervertebral disc calcifications.
• Collagen vascular disease:
  • Dermatomyositis: Shown above. Look for muscle, fascial or subcutaneous calcifications.
  • Scleroderma: Soft-tissue calcifications may be diffuse or focal, with an amorphous or linear, sheetlike appearance
• Tumors/masses: Lipoma, synovial cell sarcoma, infantile myofibromatosis, venous malformations, metastatic osteosarcoma.
• Calcium pyrophosphate dihydrate crystal deposition disease:
• Infection: Parasitic infestation, cysticercosis, dracunculiasis.
• Tumoral calcinosis: Hereditary disease of phosphate metabolic dysfunction that leads to the formation of characteristic lobulated, well-demarcated soft tissue calcifications distributed most commonly around the extensor surface of large joints.

References

• Olsen KM, Chew FS. Tumoral calcinosis: pearls, polemics, and alternative possibilities. Radiographics. 2006 May-Jun;26(3):871-85.
• Seipel R, Langner S, Platz T, Lippa M, Kuehn JP, Hosten N. Neurogenic heterotopic ossification: epidemiology and morphology on conventional radiographs in an early neurological rehabilitation population. Skeletal Radiol. 2011 Feb 18.