myositis ossificans progressiva


my·o·si·tis os·sif·'i·cans pro·gres·si·'va

a rare and frequently fatal mutation, beginning in early life, characterized by progressive ossification of the muscles; it is not strictly a myositis, but a noninflammatory ossification.
A rare idiopathic or autosomal dominant MIM 135100 condition of irregular penetration and pre-pubertal onset, in which connective/interstitial tissues undergo extensive fibrosis and heterotopic ossification of ligaments, tendons, muscle, fascia, aponeuroses and skin, first seen in late childhood as firm masses. The abnormal development of bone may lead to stiffness in affected areas and may also limit movement in affected joints, e.g., knees, wrists, shoulders, spine, and/or neck
DiffDx Osseous metaplasia, myositis ossificans, extraskeletal osteosarcoma