Intraosseous pseudotumor in a child with hypofibrinogenemia.

Intraosseous pseudotumor (i.e. chronic, encapsulated, hemorrhagic fluid collection that can be seen in any portion of the tubular bones) is an uncommon complication of severe hemophilia; however, it can occur with other rare bleeding disorders. We present the case of an 11-year-old girl with hypofibrinogenemia who had multiple intramedullary lesions that were consistent with intramedullary pseudotumor associated with this rare bleeding disorder. Percutaneous biopsy of a pseudotumor is contraindicated due to the high prevalence of complications, including life-threatening bleeding. Therefore, radiologists should make the diagnosis with characteristic MR imaging findings in a patient with a severe coagulation disorder.