MR imaging of intra-osseous hemophilic pseudotumor: case report and review ofthe literature.

Hemophilic pseudotumor (PT) is a very rare complication of hemophilia consisting of a chronic, encapsulated, hemorrhagic fluid collection occurring both in the soft tissues and/or bone. Radiological features of osseous hemophilic PT are nonspecific and mimic several other benign or malignant bone tumors, or infectious processes. Magnetic Resonance Imaging (MRI) findings of PT involving the bone are only rarely described. The appearance on MRI seems non-specific, but invariably there are heterogeneous low- and high-signal intensity areas on both pulse sequences, reflecting the presence of blood products in various stages of evolution. Although the diagnosis is usually made on the location of the lesion and by the knowledge of the underlying disease, the radiologist should be aware of the imaging characteristics, in order to avoid misinterpretation as a tumoral or infectious lesion, as biopsy of these lesions is contraindicated.