Calcinosis of the Gastrocnemius Muscle in Juvenile Dermatomyositis: A Case Report of Successful Surgical Treatment

Summary: Juvenile dermatomyositis is a rare pediatric inflammatory myopathy characterized by proximal muscle weakness and typical skin lesions. Although most patients achieve remission, up to 40% develop calcinosis, which may cause significant long-term morbidity. Management remains challenging, and surgical intervention is generally discouraged due to the risk of recurrence, ectopic ossification, and functional impairment. This case describes a 45-year-old man with a history of juvenile dermatomyositis in long-term remission who developed a spontaneous, painless swelling of the right calf. Imaging revealed extensive calcifications and soft tissue edema within the gastrocnemius muscle, initially interpreted as a hematoma in calcified tissue. After 2 months, the lesion became infected. Despite multiple debridements, antibiotics, and negative pressure wound therapy, the infection progressed and ultimately resulted in right-sided infective endocarditis. Magnetic resonance imaging demonstrated that calcinosis was confined to the medial gastrocnemius. Given persistent infection and failure of conservative treatment, a multidisciplinary team performed complete surgical excision of the medial gastrocnemius and its calcified extension into the Achilles tendon. Postoperative recovery was uncomplicated, and the patient regained full function. At 1 year, imaging showed no recurrence of calcinosis and full integrity of the Achilles tendon. This Case Report demonstrates that, in selected cases, when calcinosis is confined to a single muscle, complete surgical excision can provide a definitive cure, restore function, and prevent recurrence.