Rare form of intramedullary osteosclerosis in the tibia

The intramedullary osteosclerosis (IMOS) is a rare condition with no specific radiographic features - except the increased bone formation, which is no due to heredity, infection, acute trauma or system disorders such as skeletal dysplasia. IMOS is usually diagnosed randomly - after imiging study of the affected leg - which usually has pain that intensifies with physical activity. The laboratory findings are typically normal. Intramedullary osteosclerosis may affect a single or multiple bones without clear periosteal reaction, soft-tissue swelling, nor nidus. For being a rare condition and because of the lack of certain specific features the intramedullary osteosclerosis is still not well understood. This is why the diagnostic process is difficult and usually comes with delay. A 14-years-old patient active athlete is admitted in the clinic with complains of mild, intermittent pain in the right thigh, aggravating with physical activity. The symptoms first appear 3 months ago , with no trauma or other conditions presented. Clinical examination revealed palpable discrete swelling of the soft tissues. After series of radiographs, CT and MRI of the left thigh - a not-well-defined, localized periosteal reaction is noted and almost full oblitaration of the intramedullary canal of the right tibia in its proximal third.