Calcific myonecrosis mimicking an invasive soft-tissue neoplasm. A case report and review of the literature.

Abstract

Calcific myonecrosis has been reported as a late sequela of compartment syndrome, injury to the common peroneal nerve, and injury to the lower extremity without documented compartment syndrome or neurological injury1-8,13-19. This rare condition has been reported to occur ten to sixty-four years after the initial injury and typically presents as an enlarging mass in the anterior compartment of the leg. The characteristic radiographic appearance is that of a large fusiform soft-tissue mass in the anterior compartment, with peripheral plaque-like calcifications and usually with a well defined border. The calcifications may extend along fascial planes13. Erosion of bone had been reported in only four patients8,13. The benign radiographic appearance usually allows the lesion to be differentiated from an enlarging malignant mass in the soft tissues7. A sterile abscess usually is found at the time of operative treatment, but there is a high prevalence of chronic draining sinuses and secondary infection3,7,8,18. We report the case of a patient who was seen because of a painless, enlarging mass in the anterior and lateral compartments of the leg thirty years after he had been hit by an automobile. At the time of the initial injury, he had sustained damage to the knee, a partial sciatic-nerve palsy, and a probable compartment syndrome of the leg. The case of our patient differs substantially from previously reported cases of calcific myonecrosis in that there was extensive erosion of bone, giving the lesion the appearance of an invasive neoplasm. A forty-nine-year-old man was referred for evaluation of a slowly enlarging mass in the right leg. Thirty years previously, he had been struck by an automobile while walking. He stated that he had sustained …