Myositis ossificans: a rare neonatal presentation.

Myositis ossificans is a benign, ossifying, soft-tissue pseudotumor that most commonly occurs in men ages 30-40 years after trauma. Myositis ossificans may also occur in children, but it is extremely rare in those younger than 10 years of age. While myositis ossificans can often mimic malignant soft-tissue tumors, it has many unique findings that can aid in diagnostic differentiation. This differentiation is critical to avoid unnecessary risk with potentially harmful procedures. We present a very unusual presentation of myositis ossificans in the immediate post-birth perinatal period, as well as a review of key imaging findings.