CASE 151
By: Dr. Nizar Al-Nakshabandi MD, FRCPC
HISTORY: 60-year-old with leg pain and past medical history of tibial fracture.
What are your findings?
What is the differential diagnosis?
What are the causes?
FINDINGS:
The plain films A and B demonstrate fusiform masses of peripherally oriented plate like amorphous calcifications. They are oriented in the sheet like pattern and involve the muscles of the leg laterally.
CT scan demonstrates the fusiform cystic lobulated components of this calcification, some of which have eroded into the bone due to their chronic nature. Anterior muscle group atrophied with fat replacement.
DIFFERENTIAL DIAGNOSIS:
The differential diagnosis of soft tissue calcification is as follow:
· Calcific myonecrosis.
· dystrophic soft tissue calcification (most common), e.g. chronic venous insufficiency.
· vascular, e.g. arterial calcification, phleboliths.
· metabolic, e.g. CPPD (causing chondrocalcinosis), metastatic calcification, idiopathic tumoural calcinosis.
· autoimmune diseases, e.g. scleroderma, dermatomyositis.
· infection, e.g. cysticercosis.
· neoplasm, e.g. primary or metastatic osteosarcoma, synovial osteochondromatosis.
· trauma, e.g myositis ossificans, tendonitis.
DIAGNOSIS:
Calcific myonecrosis.
PEARLS AND DISCUSSION:
Calcific myonecrosis is a rare posttraumatic condition characterized by a vacuum formation of dystrophic calcification almost exclusively in the lower limb.
It is thought that the ischemia that appears because of the complication of compartment syndrome resulting in calcific myonecrosis. The current hypothesis is that the initial compartment syndrome decreases the circulation within the limited space resulting in necrosis and fibrosis. After some time, repeated intralesional hemorrhage causes the mass to enlarge and get calcified. The most common site is the lower leg with the anterior compartment most frequently affected.
Calcific Myonecrosis is a benign diagnosis and although uncomfortable and disfiguring should not prompt a biopsy as devastating results may occur. It is one of those condition that should be considered a do not touch lesion.
FURTHER READING:
1- O'Dwyer HM, Al-Nakshabandi NA, Al-Muzahmi K et-al. Calcific myonecrosis: keys to recognition and management. AJR Am J Roentgenol. 2006;187 (1): W67-76. doi:10.2214/AJR.05.0245 - Pubmed citation
2- Holobinko JN, Damron TA, Scerpella PR et-al. Calcific myonecrosis: keys to early recognition. Skeletal Radiol. 2003;32 (1): 35-40. doi:10.1007/s00256-002-0549-1 - Pubmed citation
3. Snyder BJ, Oliva A, Buncke HJ. Calcific myonecrosis following compartment syndrome: report of two cases, review of the literature, and recommendations for treatment. J Trauma. 1995;39 (4): 792-5.
