Image Description
Treatment & Prognosis: Myositis ossificans (MO) is a self-limiting benign lesion that is cured by simple excision. The prognosis is excellent. Some cases regress spontaneously. If it is partially excised in early phase, it may continue to grow for sometime.
There is controversy regarding any malignant potential of MO. A few cases of extraskeletal osteosarcoma purportedly arising by malignant transformation of MO have been documented; however, the idea of MO being able to transform to a sarcoma is not universally accepted.
About this image: As myositis ossificans matures, it is composed of increasing amounts of mature lamellar bone. A sampling of such foci may be mistaken for an osteoma. Long standing lesions may also develop hematopoietic or fatty marrow (seen in this case).
There is controversy regarding any malignant potential of MO. A few cases of extraskeletal osteosarcoma purportedly arising by malignant transformation of MO have been documented; however, the idea of MO being able to transform to a sarcoma is not universally accepted.
About this image: As myositis ossificans matures, it is composed of increasing amounts of mature lamellar bone. A sampling of such foci may be mistaken for an osteoma. Long standing lesions may also develop hematopoietic or fatty marrow (seen in this case).