Abstract
Myositis ossificans (MO) is characterized by abnormal heterotopic ossification formation, typically involving muscles, tendons, ligaments, fascia, and aponeurosis. It can be categorized into nonhereditary and hereditary types, with the latter being a distinct entity with a separate pathophysiology and treatment approach. The pathophysiology of MO formation remains to be fully elucidated. MO is most commonly observed in muscle tissue as a solitary lesion. The disease has been reported to occur in all ages, including the very young and in atypical locations, including hands, feet, ribs, head and neck. The present case report describes an unusual pseudomalignant form of MO in the breast. The authors discuss the clinical and morphological characteristics of the tumor and its treatment options.