Calcific myonecrosis of the lower leg: diagnosis and options of treatment.

INTRODUCTION: Calcific myonecrosis is a rare condition characterized by a calcified lesion. Because this lesion sometimes presents as a huge mass with unique radiographic characteristics, it can be confused with soft tissue sarcoma. The appropriate treatment is still controversial. We report here three cases diagnosed as calcific myonecrosis of the lower leg and discuss its clinical presentation, diagnosis and options for treatment. PATIENTS AND METHODS: Three patients presented as expanding masses in the anterior or lateral compartment muscle and occurred more than 10 years after an initial injury. Plain radiographs showed a large soft tissue mass with extensive amorphous calcifications. Computed tomograms revealed a low-density tumor with scattered calcifications. Magnetic resonance imaging showed a bright, high-signal area on T2-weighted imaging consistent with fluid. Two patients underwent excisions for histopathological evaluation and one was treated conservatively because of the absence of disability.
RESULTS: Two operative patients had no complication and the returned to work without evidence of deterioration of the disease. In a patient treated conservatively, the mass was not enlarged and was still painless at 2-year follow-up.
CONCLUSION: The key points for diagnosis were (1) amorphous liner calcification, (2) anterior or lateral compartment, (3) previous injury (several decades) of the tibia or femur, and (4) compartment syndrome. Although calcific myonecrosis is not commonly encountered, it must be considered in the differential diagnosis of an expanding intramuscular mass. In asymptomatic masses where the diagnosis is recognized, observation may be possible and unnecessary aggressive surgical intervention should be avoided.