Myositis ossificans - A case report and review of literature

Abstract

Associated with abnormal bone formation with various localizations, myositis ossificans is both a diagnostic and a therapeutic challenge due to its rare occurrence and clinical presentation. We examined a case of a 14 year old male patient who was diagnosed with the clinical suspicion of myositis ossficans. Contrast substance MRI revealed the presence of a strictly intramuscular mass located in the 1/3 proximal area of the left thigh, at the level of the vastus lateralis muscle. Macroscopic examination of the specimens revealed multiple, irregular tissue fragments, forming a mass of about 5,5/6/1,2 cm. Additional immunohistochemical analysis was made using the following panel of markers: SMA, Vimentin, Desmin, protein S100, NSE and GFAP. Vimentin was intensely positive in osteoblasts, partially in osteocytes, in the stromal fibroblasts/ fibrocytes, in adipocytes and in the vascular wall, in endothelial and smooth muscle cells. GFAP and NSE were negative.